Abstract

The extraction of bio-compounds from medicinal plants provides opportunities for using the plant extract for health benefits. Rosa canina L. is considered a natural superfood, and the valorization of its active compounds requires an extraction technique that ensures a suitable extraction yield while preserving the compounds' activity. In our study, infrared laser irradiation (IRLIR) technology was used for the first time in the bioactive compound's extraction from Rosa canina L. Different solvents (water-ethanol, hexane-ethanol) and different extraction times were tested to obtain a high extraction yield. Chromatographic and spectrophotometry methods were used to monitor the profile of bioactive compounds and the antioxidant activity of the extracts. The results obtained for IRLIR were compared with those obtained by accelerated solvent extraction (ASE), an advanced extraction method. The IRLIR technology proved to be a more reliable analytical tool for the extraction of (+)-catechin, gallic acid, and lutein. In addition, a richer extract formula was obtained by IRLIR extraction with respect to ASE, with the IRLIR process ensuring a short extraction time, low volume of the extraction solvent, low energy consumption, and a less expensive device.

Abstract

The purpose of this study was to extract the lipophilic fraction from one of the largest source of waste in the industrial sector, namely, the tomato residue from processing the fruit. In order to make this process more environmentally sustainable, this study used a green extraction protocol employing natural deep eutectic solvents (NADESs) combined with a less energy-consuming technology, the ultrasound-assisted extraction (UAE) method, to simultaneously recover carotenoids and tocopherol from dried powder tomato waste. Two NADESs, one hydrophilic and one hydrophobic, were prepared and compared to support high extraction efficiency and increase the stability of the extracted compounds. The optimal extraction parameters were identified as choline chloride:1,3-butanediol (1:5)-based NADES, a solid-to-liquid ratio of 1:20 (w/v), time of extraction 12 min, temperature 65 degrees C, radiation frequency 37 Hz, and an ultrasound power level of 70%. The extraction process was intensified and resulted in extracts rich in lycopene (215.13 +/- 4.31 mu g/g DW), beta-carotene (206.95 +/- 3.27 mu g/g DW), and tocopherol (130.86 +/- 8.97 mu g/g DW) content, with the highest antioxidant capacity 93.84 +/- 0.18 mM Trolox equivalent. Incorporating NADESs for the extraction of bioactive compounds offers numerous benefits, such as improved sustainability, enhanced extraction efficiency, better protection of sensitive compounds, and reduced environmental impact. These advantages make NADESs a promising alternative to traditional organic solvents, especially in industries that require natural, green, and efficient extraction processes for valuable bioactive molecules.

Abstract

Cost-effective chemosensors have become an indispensable tool for sustainable monitoring in food safety and processing, where there is an urgent need for affordable, efficient, and real-time analytical solutions. This review discusses recent advances in low-cost chemosensor technologies, highlighting developments in materials, miniaturization, and integration into portable and accessible platforms. The focus is on applications for detecting contaminants, monitoring quality, and ensuring safety in food production and processing. This review also addresses the challenges related to sensor sensitivity, selectivity, and operational stability and provides insights into future directions and the role of low-cost chemosensors in supporting sustainable practices in these important sectors.

Abstract

The present study evaluates the potential of sorghum, soybean, and corn residues, grown on unproductive soils from a coal mining region, to generate green energy through pyrolysis and gasification, Sharing knowledge in biomass valorization, the study also delivers explicit insights, useful to various stakeholders (local authorities, energy companies, and policymakers) regarding feedstock selection and process optimization, according to their specific goals. the aim is to optimize the composition of the developed synthesis gases, which are rich in H-2 and CH4, and the energetic properties through the variation of the process conditions. After a comprehensive feedstock characterization, the synthesis gases were continuously investigated through mass spectrometry to assess the chemical properties and calculate the physical ones. The obtained data were analyzed using evolutional charts and statistical tools (Principal Component Analysis, Hierarchical Cluster Analysis), emphasizing the interrelationships between feedstock characteristics and syngas composition. Key findings indicate that sorghum pyrolysis at 800 degrees C-1000 degrees C yielded the highest H-2, while corn generated more CH4 and CO, along with the highest calorific value. The statistical analysis demonstrated correlations between gas yields and biomass properties (e.g. hemicellulose, C/H, and O/H ratios). Biomass type had a greater influence on each process compared to the temperature.

Abstract

A stable layer of 4-phenyl isothiocyanate (4-PITC) was successfully electrografted on glassy carbon electrode (GCE). The electrode modification process was performed in three sequential steps in a single solution: (1) reduction by chronoamperometry of the nitro groups of 4-NITC to amino moieties (2) in situ reaction of amino with nitrous acid to obtain unstable diazonium functional groups and (3) electrografting by chronopotentiometry of diazonium. A thin optimal layer with minimum surface fouling was obtained. The formation of the organic film was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrode was used for detection of Pb(II) and Fe(II) by differential pulse voltammetry (DPV). Under optimal conditions, the limit of detection 1.2 mu g L-1 for Pb(II) and of 2.0 mu g L-1 for Fe(II) were achieved. The developed electrode was successfully applied to detect Pb(II) and Fe(II) in injectable iron pharmaceuticals used to treat iron deficiency anemia simultaneous with investigation of contamination by Pb(II).

Abstract

The identification of melatonin in grapes has led to the publication of numerous studies on melatonin in wines, and the aim of this study was to perform a systematic review and meta-analysis of published data on melatonin concentrations in wines. In this context, international databases such as Scopus, Web of Science and PubMed were searched for relevant articles (437) up to 29 March 2025. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used. A total of 15 studies from eight countries, involving various wine types and analytical methods, were included in the meta-analysis. Considerable analytical variation was observed across studies, and high-performance liquid chromatography (HPLC) coupled with either mass spectrometry (MS) or fluorescence (FL) detection was shown to be the most accurate and sensitive method for quantifying melatonin. The highest concentrations were found in Spanish red Tempranillo wine, Romanian white Noah wine, and Romanian ros & eacute; Lidia wine. Red wines, particularly those produced from Cabernet Sauvignon (CS) grapes, were the most frequently studied. The results of this work provide a clearer picture of melatonin levels in wine. Further research is needed to explore the implications of melatonin content in wine for human health and the wine industry.

Abstract

A nitrogen-doped nanocrystalline electrochemical graphite sensor for the sensitive determination of oleuropein (OL) from extra virgin olive oils (EVOOs) is presented. The sensor was developed by the deposition of nanocrystalline graphite (NCG) using plasma-enhanced chemical vapour deposition (PECVD) on silicon wafers. Scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction analysis (XRD) were used to characterise the microstructure and morphology of the developed materials. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV) were used to investigate the electrochemical properties of the material and the performance of the sensor. The developed sensor showed good analytical performance against OL over a concentration range of 5.00-500.00 mu M, with a good detection limit of 3.93 mu M and a good sensitivity of 0.057 mu A mu M-1. The reproducibility of the electrochemical sensor was excellent, with a relative standard deviation (RSD) of 8.56% for seven measurements.

Abstract

The present study evaluated three green extraction methods, accelerated solvent extraction (ASE), ultrasound-assisted extraction (UAE), and laser irradiation extraction (LE), for the polyphenolic compounds and vitamin C extraction of Cornus mas L. and Crataegus monogyna fruit extracts. The polyphenols and vitamin C of extracts were quantified using HPLC-DAD, and the total phenolic content, flavonoid content, antioxidant activity (DPPH and reducing power), and antidiabetic activity were also studied. The antidiabetic activity was examined by the inhibition of alpha-amylase and alpha-glucosidase, and in vitro on a beta TC cell line (beta-TC-6). The results showed significant differentiation in the extraction yield between the methods used, with the ASE and LE presenting the highest values. The C. mas fruit extract obtained by ASE exhibited the best antioxidant activity, reaching an IC50 value of 31.82 +/- 0.10 mu g/mL in the DPPH assay and 33.95 +/- 0.20 mu g/mL in the reducing power assay. The C. mas fruit extracts obtained by ASE and LE also have the highest inhibitory activity on enzymes associated with metabolic disorders: alpha-amylase (IC50 = 0.44 +/- 0.02 mu g/mL for the extract obtained by ASE, and 0.11 +/- 0.01 mu g/mL for the extract obtained by LE at combined wavelengths of 1270 + 1550 nm) and alpha-glucosidase (IC50 of 77.1 +/- 3.1 mu g/mL for the extract obtained by ASE, and 98.2 +/- 4.7 mu g/mL for the extract obtained by LE at combined wavelengths of 1270 + 1550 nm). The evaluation of in vitro antidiabetic activity demonstrated that the treatment with C. mas and C. monogyna fruit extracts obtained using ASE stimulated the insulin secretion of beta-TC-6 cells, both under normal conditions and hyperglycemic conditions, as well. All results suggest that C. mas and C. monogyna fruit extracts are good sources of bioactive molecules with antioxidant and antidiabetic activity.

Abstract

We have developed a bienzymatic biosensor that contains acetylcholinesterase together with butyrylcholinesterase co-immobilized on the same electrode modified with a stabilized copper containing Prussian blue electrodeposited on electrodes coated with 4-aminothiophenol monolayer using diazonium chemistry and copper nanoparticles for improved sensitivity. There are organophosphorus and carbamate neurotoxic insecticides that inhibit only one of the two enzymes, e.g., pirimicarb inhibits butyrylcholinesterase at much lower concentrations than acetylcholinesterase while methomyl inhibits only acetylcholinesterase. Our system is simple and in a single measurement provides a sensitive signal for insecticides' presence based on the inhibition of the enzyme with the highest affinity for each toxic compound. The limits of detection are 50 ng/mL pirimicarb for the bienzymatic biosensor in comparison with 400 ng/mL pirimicarb for the acetylcholinesterase biosensor and 6 ng/mL methomyl for the bienzymatic biosensor, while inhibition is obtained for the butyrylcholinesterase biosensor at 700 ng/mL.

Abstract

In recent years, various studies have been carried out to increase the concentration of antioxidant active principles in red wines as a consequence of the effects of winemaking techniques on the polyphenols content. In this study, in order to obtain the most optimal wine in terms of content and efficiency of antioxidant activity, various winemaking technologies (punching-down and pumping-over maceration) were tried with diverse gradations (Feteasca Neagra and Cabernet Sauvignon wines) and the addition of different concentrations of melatonin in must. Suitable HPLC and spectrophotometric methods were used to follow the evolution of the antioxidant compounds from wines during aging (for 12 months). After comparing the acquired results, an increase was observed in the antioxidant compound concentrations, particularly in resveratrol (85%), peonidin-3-glucoside (100%) or cyanidin-3-glucoside (100%), and antioxidant activity (10-40%). The most enriched wine was obtained in the case of Feteasca Neagra by the addition of 0.5 mg of melatonin per 1 kg of must using the punch-down technology and, in the case of Cabernet Sauvignon, by the addition of 0.05 mg of melatonin per 1 kg of must using the pumping-over technique. This study can provide winemakers with an approach to enhance red wines with antioxidant compounds.

Abstract

The present study evaluated the antioxidant and antidiabetic properties of Medicago sativa and Solidago virgaurea extracts enriched in polyphenolic compounds. The extracts were obtained by accelerated solvent extraction (ASE) and laser irradiation. Then, microfiltration was used for purification, followed by nanofiltration used to concentrate the two extracts. The obtained extracts were analyzed to determine their antioxidant activity using DPPH radical scavenging and reducing power methods. The antidiabetic properties have been investigated in vitro on a murine insulinoma cell line (beta-TC-6) by the inhibition of alpha-amylase and alpha-glucosidase. M. sativa obtained by laser irradiation and concentrated by nanofiltration showed the highest DPPH center dot scavenging (EC50 = 105.2 +/- 1.1 mu g/mL) and reducing power activities (EC50 = 40.98 +/- 0.2 mu g/mL). M. sativa extracts had higher inhibition on alpha-amylase (IC50 = 23.9 +/- 1.2 mu g/mL for concentrated extract obtained after ASE, and 26.8 +/- 1.1), while S. virgaurea had the highest alpha-glucosidase inhibition (9.3 +/- 0.9 mu g/mL for concentrated extract obtained after ASE, and 8.6 +/- 0.7 mu g/mL for concentrated extract obtained after laser extraction). The obtained results after evaluating in vitro the antidiabetic activity showed that the treatment with M. sativa and S. virgaurea polyphenolic-rich extracts stimulated the insulin secretion of beta-TC-6 cells, both under normal conditions and under hyperglycemic conditions as well. This paper argues that M. sativa and S. virgaurea polyphenolic-rich extracts could be excellent natural sources with promising antidiabetic potential.

Abstract

We have developed a bienzymatic biosensor that contains acetylcholinesterase together with butyrylcholinesterase co-immobilized on the same electrode modified with a stabilized copper containing Prussian blue electrodeposited on electrodes coated with 4-aminothiophenol monolayer using diazonium chemistry and copper nanoparticles for improved sensitivity. There are organophosphorus and carbamate neurotoxic insecticides that inhibit only one of the two enzymes, e.g., pirimicarb inhibits butyrylcholinesterase at much lower concentrations than acetylcholinesterase while methomyl inhibits only acetylcholinesterase. Our system is simple and in a single measurement provides a sensitive signal for insecticides’ presence based on the inhibition of the enzyme with the highest affinity for each toxic compound. The limits of detection are 50 ng/mL pirimicarb for the bienzymatic biosensor in comparison with 400 ng/mL pirimicarb for the acetylcholinesterase biosensor and 6 ng/mL methomyl for the bienzymatic biosensor, while inhibition is obtained for the butyrylcholinesterase biosensor at 700 ng/mL. Graphical Abstract: (Figure presented.) © The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature 2024.

Abstract

In recent years, increased attention has been paid to the recovery of bioactive compounds from waste and by-products resulting from the agro-industrial sector and their valorization into new products, which can be used in the health, food, or agricultural industry, as innovative and sustainable approaches to waste management. In this work, two of these by-products resulting from the fruit-processing industry were used for the recovery of bioactive compounds (polyphenols), namely lingonberry pomace (Vaccinium vitis-idaea) and grape pomace (Vitis vinifera). Two green extraction techniques were employed to obtain hydroalcoholic extracts (solvent: 50% EtOH, 10% mass): ultrasound-assisted extraction (UAE) and accelerated solvent extraction (ASE). The extracts were subjected to micro- and ultrafiltration processes, and further analyzed to determine the bioactive compound content through spectrophotometric (UV-Vis) and chromatographic (HPLC-PDA) methods. Additionally, the extracts exhibited significant enzyme inhibition, particularly against alpha-amylase and beta-glucosidase, suggesting potential anti-diabetic properties. The extracts characteristics, polyphenolic content, antioxidant capacity and enzyme inhibitory ability, were statistically compared, and significant differences were found between the two extraction methods. The grape pomace concentrated extracts showed a pronounced inhibitory activity on both analyzed enzymes compared to the lingonberry pomace concentrated extracts, closer to the standard used; e.g., IC50 alpha-amylase = 0.30 +/- 0.01 mu g/mL (IC50 acarbose = 0.3 +/- 0.01 mu g/mL), IC50 alpha-glucosidase = 0.60 +/- 0.01 mu g/mL (IC50 acarbose = 0.57 +/- 0.02 mu g/mL). These findings highlight the potential of agro-industrial residues as bioactive compound resources, with their valorization through application in food, nutraceutical, or pharmaceutical industries therefore contributing to the sustainable development and promotion of circular economy principles with the recovery of valuable inputs from plant by-products.

Abstract

A new molecularly imprinted polymer (MIP)-based disposable electrochemical sensor for dipyridamole (DIP) determination was obtained. The sensor was rapidly prepared by potentiodynamic electrochemical polymerization on a pencil graphite electrode (PGE) using curcumin (CUR) as a functional monomer and DIP as a template molecule. After the optimization of the conditions (pH, monomer-template ratio, scan rate, number of cyclic voltammetric cycles applied in the electro-polymerization process and extraction time of the template molecule) for MIP formation, DIP voltammetric behavior at the modified electrode (MIP_PGE) was investigated. DIP oxidation took place in a pH-dependent, irreversible mixed diffusion-adsorption controlled process. Differential pulse voltammetry (DPV) and adsorptive stripping differential pulse voltammetry (AdSDPV) were used to quantify DIP from pharmaceutical and tap water samples. Under optimized conditions (Britton-Robinson buffer at pH = 3.29), the obtained linear ranges were 5.00 x 10-8-1.00 x 10-5 mol/L and 5.00 x 10-9-1.00 x 10-7 mol/L DIP for DPV and AdSDPV, respectively. The limits of detection of the methods were 1.47 x 10-8 mol/L for DPV and 3.96 x 10-9 mol/L DIP for AdSDPV.

Abstract

Abstract

Abstract

Our study was aimed to characterise the hemp seeds and cake from the point of view of proximate chemical composition and bioactive compounds, as alternative feedstuffs for ruminants' nutrition. Hemp seeds and cake presented high concentrations of several trace minerals (e.g., iron, manganese, zinc), especially hemp cake had the higher content of these compounds (0.001

Abstract

Lately, there has been increased interest in the development of phytochemical alternatives for the prevention and treatment of type 2 diabetes, the alternatives that are able to reduce or prevent glucose absorption by inhibiting digestive enzymes. In this context, this study aims to analyze the inhibitory alpha-amylase and alpha-glucosidase activities of Artemisia abrotanum and Symphytum officinale polyphenolic compound-rich extracts obtained by membrane technologies (micro- and ultrafiltration). Polyphenols and flavones content, HPLC-MS polyphenolic compounds profiling, antioxidant activity, and cytotoxic potential of these herbs were determined. Major phenolic acid compounds were chlorogenic acid, ellagic acid, caffeic acid, and rosmarinic acid. The flavone content was higher in the case of A. abrotanum extracts, and the major compounds were rutin and umbelliferone. The polyphenolic-rich extract of A. abrotanum had the highest quantities of polyphenols, 977.75 mu g/mL, and flavones, 552.85 mu g/mL, as well as a pronounced alpha-amylase inhibitory activity (IC50 1881.21 +/- 1.8 mg/mL), a value close to acarbose inhibitory activity (IC50 1110.25 +/- 8.82 mg/mL) that was used as the control for both enzymes. The alpha-glucosidase inhibitory activity was higher for both herb extracts, more pronounced for S. officinale polyphenolic-rich extract (IC50 291.56 +/- 2.1 mg/mL), a value higher than that of acarbose (IC50 372.35 +/- 3.2 mg/mL). These plants show potential as a complementary therapy for type 2 diabetes management.

Abstract

Ultrasound generates cavities in liquids with high-energy behaviour due to large pressure variations, leading to (bio)chemical effects and material modification. Numerous cavity-based treatments in food processes have been reported, but the transition from research to industrial applications is hampered by specific engineering factors, such as the combination of several ultrasound sources, more powerful wave generators or tank geometry. The challenges and development of cavity-based treatments developed for the food industry are reviewed with examples limited to two representative raw materials (fruit and milk) with significantly different properties. Both active compound extraction and food processing techniques based on ultrasound are taken into consideration.

Abstract

In recent years, the wine industry has shown a considerable degree of interest in the occurrence of melatonin in wines. Sample pretreatment may be the most important step in trace analysis. Since wine is a complex matrix and melatonin is present in low amounts (ppb), an adequate extraction technique is required. In this study, the effect of several extraction methods, such as solid phase extraction (SPE), Quick, Easy, Cheap, Effective, Rugged, and Safe extraction (QuEChERS), and dispersive liquid-liquid micro-extraction (DLLME) was studied and the variable parameters that can arise throughout the extraction process were optimized to obtain the best results. A high-performance liquid chromatography with fluorescence detector (HPLC-FL) method was adapted and validated, including measurement uncertainty, for the analysis of melatonin in wines and to assess the efficiency of the extraction yield. After comparing the acquired results, the DLLME method was optimized. Extraction recoveries values ranging from 95 to 104% demonstrated that the approach may be successfully applied for the extraction and concentration (enrichment factor of almost eight) of melatonin in wine samples prior to HPLC-FL analysis. The first report of melatonin levels in Feteasca Neagra wines has been made. The data obtained for Cabernet Sauvignon revealed that the final levels of melatonin in the wines are dependent on the winemaking process.

Abstract

Until recently, the main antioxidant role among wine constituents was attributed to polyphenolic compounds, but once the presence of melatonin in wines was confirmed, an interesting new field of research opened up due to its possible synergistic effects with other antioxidants in the winemaking process, which may lead to a change in the profile of polyphenolic compounds and antioxidant activity. In order to investigate the evolution of active principles from the phenylpropanoid metabolism associated with the synergistic effects of melatonin, for the first time, a melatonin treatment was performed in the pre-stage of the different winemaking processes of Feteasca Neagra and Cabernet Sauvignon wines with different melatonin concentrations. After comparing the acquired results for the evolution of the polyphenolic compound profile and antioxidant activity of treated wines, we ascertained an increase in the antioxidant compound concentrations, especially in resveratrol, quercetin, and cyanidin-3-glucoside, directly proportional to the used melatonin concentration; an intensification in activity of PAL and C4H enzymes; and the modification in the expression of specific anthocyanin biosynthesis genes, especially UDP-D-glucose-flavonoid-3-O-glycosyltransferase. It was also shown that the application of melatonin in the pre-stage of the winemaking process can be successfully used to obtain red wines with increased antioxidant activity (almost 14%).

Abstract

A new method for the determination of the antiplatelet drug dipyridamole (DIP) in pharmaceuticals using a molecularly imprinted polymer (MIP)-modified pencil graphite electrode (PGE) is proposed. The modified electrode was prepared simply and rapidly by electropolymerization of caffeic acid (CA) in the presence of DIP and subsequent DIP extraction with ethanol, resulting in a cost-effective, eco-friendly disposable modified electrode (MIP_PGE). Several working conditions (monomer and template concentration, number of voltametric cycles, scan rate extraction time, and solvent) for the MIP_PGE preparation were optimized. The differential pulse voltammetric (DPV) oxidation signal of DIP obtained at MIP_PGE was 28% higher than that recorded at bare PGE. Cyclic voltammetry emphasized DIP irreversible, pH-dependent, diffusion-controlled oxidation at MIP_PGE. Differential pulse and adsorptive stripping voltammetry at MIP_PGE in phosphate buffer solution pH = 7.00 were applied for the drug quantitative determination in the range of 1.00 x 10(-7)-1.00 x 10(-5) and 1.00 x 10(-8)-5.00 x 10(-7) mol/L DIP, respectively. The obtained limits of detection were at the tens nanomolar level.

Abstract

The administration of chokeberry extract in vitro in the GIS1 system was evaluated for the modulation capacity of the dysbiotic pattern resulting from the consumption of stevia. The microbial pattern determined by molecular method, the metabolomic one (fatty acids), the evolution of the antioxidant status, and the cytotoxic effect were determined comparatively for six months. This study presented for the first time that Aronia extract has a strong antimicrobial effect but also a presence of new organic acids that can be used as a biomarker. The functional supplement had the impact of a gradual increase in antioxidant status (DPPH scavenging activity) for up to three months and a subsequent decrease correlated with the reduction of the microbial load (especially for Enterobacteriaceae). The effect on metabolomic activity was specific, with butyric acid being generally unaffected (0.6-0.8 mg/mL) by the antimicrobial effect manifested after three months of administration. The pH was strongly acidic, corresponding to the constant presence of maximum values for acetic and lactic acid. The non-selective elimination of a part of the microbiota could also be correlated with a decrease in metabolomic efficiency. The results in the GIS1 system indicated for the first time that the controlled use of this extract had a pronounced antimicrobial and cytotoxic effect. This has helped to correct the dysbiotic pattern that results after the long-term use of sweeteners based on an increase of 0.2 log UFC/mL for favorable strains.

Abstract

Brewer's spent yeast (BSY) is a byproduct of the beer industry, rich in proteins and bioactive compounds. The effects of BSY were investigated through a 6-week feeding trial on 30 lactating dairy Blackhead sheep (54.7 +/- 5.66 kg, 177.34 days in milk) distributed under a completely randomised design in two groups: a control group (with soybean meal and sunflower meal as protein sources), and a BSY group, where soybean meal was totally replaced by BSY (5.4% inclusion, DM basis). The inclusion of BSY led to a 25% decrease in ruminal propionate and in the acetate/propionate ratio. BSY influenced the milk fatty acid profile by significantly decreasing the omega 6: omega 3 ratio and increasing the contents of caproic, capric, and lauric acids. Also, the inclusion of BSY was associated with an increase in the milk's total polyphenols. Consistently, determinations of the parameters of the milk fat's oxidative stability revealed a decrease in conjugated diene contents. Moreover, the mineral contents of milk were influenced, with an increase in Ca content noted. Overall, these results indicate that BSY represents an alternative feedstuff for ruminants' nutrition, which could have the potential to induce changes in ruminal fermentation and milk composition that are beneficial for consumers.

Abstract

Brewer’s spent yeast (BSY) is a byproduct of the beer industry, rich in proteins and bioactive compounds. The effects of BSY were investigated through a 6-week feeding trial on 30 lactating dairy Blackhead sheep (54.7 ± 5.66 kg, 177.34 days in milk) distributed under a completely randomised design in two groups: a control group (with soybean meal and sunflower meal as protein sources), and a BSY group, where soybean meal was totally replaced by BSY (5.4% inclusion, DM basis). The inclusion of BSY led to a 25% decrease in ruminal propionate and in the acetate/propionate ratio. BSY influenced the milk fatty acid profile by significantly decreasing the omega 6: omega 3 ratio and increasing the contents of caproic, capric, and lauric acids. Also, the inclusion of BSY was associated with an increase in the milk’s total polyphenols. Consistently, determinations of the parameters of the milk fat’s oxidative stability revealed a decrease in conjugated diene contents. Moreover, the mineral contents of milk were influenced, with an increase in Ca content noted. Overall, these results indicate that BSY represents an alternative feedstuff for ruminants’ nutrition, which could have the potential to induce changes in ruminal fermentation and milk composition that are beneficial for consumers. © 2023 by the authors.

Abstract

Recently, there has been increased interest in the discovery of new natural herbal remedies for treating diabetes and inflammatory diseases. In this context, this work analyzed the antidiabetic and anti-inflammatory potential of Artemisia absinthium, Artemisia vulgaris and Trigonella foenum-graecum herbs, which have been studied less from this point of view. Therefore, extracts were prepared and processed using membrane technologies, micro- and ultrafiltration, to concentrate the biologically active principles. The polyphenol and flavone contents in the extracts were analyzed. The qualitative analysis of the polyphenolic compounds was performed via HPLC, identifying chlorogenic acid, rosmarinic acid and rutin in A. absinthium; chlorogenic acid, luteolin and rutin in A. vulgaris; and genistin in T. foenum-graecum. The antidiabetic activity of the extracts was analyzed by testing their ability to inhibit alpha-amylase and alpha-glucosidase, and the anti-inflammatory activity was analyzed by testing their ability to inhibit hyaluronidase and lipoxygenase. Thus, the concentrated extracts of T. foenum-graecum showed high inhibitory activity on a-amylase-IC50 = 3.22 +/- 0.3 mu g/mL-(compared with acarbose-IC50 = 3.5 +/- 0.18 mu g/mL) and high inhibitory activity on LOX-IC50 = 19.69 +/- 0.52 mu g/mL (compared with all standards used). The concentrated extract of A. vulgaris showed increased alpha-amylase inhibition activity-IC50 = 8.57 +/- 2.31 mu g/mL-compared to acarbose IC50 = 3.5 +/- 0.18 mu g/mL. The concentrated extract of A. absinthium showed pronounced LOX inhibition activity-IC50 = 19.71 +/- 0.79 mu g/mL-compared to ibuprofen-IC50 = 20.19 +/- 1.25 mu g/mL.

Abstract

Sensitive and stable electrodes modified with 4-aminothiophenol were developed for heavy metal detection based on coordination bonds between thiol moieties and analyte. The electrodes were modified using diazonium chemistry in one step modification protocol. The presence of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) in the electrodeposition media avoids the formation of multilayers and improves the performances due to low surface passivation and good electrochemical transfer at the interface with the solution. Electrodeposition of the organic layer on the electrode surface by chronopotentiometry allowed a good control of the electrode modification process, avoids passivation, and leads to reproducible layers with improved characteristics in comparison with modifications carried out by cyclic voltammetry or chronoamperometry. The electrode was able to detect Pb(II) by differential pulse voltammetry with a linear range of 2.5-400 mu g l(-1) and the detection limit of 1.2 mu g l(-1) and Cd(II) with the calibration line in the range of 2.5-400 mu g l(-1) and a detection limit of 1.5 mu g l(-1). Low interferences were observed and the electrodes were applied for analysis of real samples: fruits pomace and waters. (C) 2022 The Electrochemical Society (ECS). Published on behalf of ECS by IOP Publishing Limited.

Abstract

Few biosensors are reported for usage in combination with the organic solvent due to their negative impact on the enzymes. The usage of ternary water-organic solvent mixtures in combination with acetylcholinesterase biosensors allows to increase the useable total content of organic solvents with minimum negative effects to a higher content in comparison with a single organic solvent in water. The combination of acetonitrile/ethanol/ water has a smaller negative effect on both enzyme activity and inhibition by insecticides in comparison with acetonitrile/methanol/water mixtures. The insecticides were eluted from solid-phase extraction (SPE) columns with a binary mixture of organic solvents acetonitrile/ethanol in 1/3 ratio and subsequently analysed with an acetylcholinesterase biosensor and the optimum total content of organic solvents of 12%. The analytical method allows the analysis of complex samples with improved selectivity and at improved limits of detection for chlorpyrifos-oxon and carbofuran analysis in river waters and soil samples. The usage of mixtures of organic solvents in combination with enzymes is an interesting approach that allows working with a higher total content of organic solvents than each individual solvent.

Abstract

This study presents the preparation of hybrid nanofiltration membranes based on poly(1,4-phenylene ether ether sulfone), polyacrylonitrile, poly(vinyl pyrrolidone), and SBA-15 mesoporous silica. Laser treatment of polymeric solutions to enhance the hydrophilicity and performance of membranes was investigated. The membranes' structure was characterized using scanning electron (SEM) and atomic force (AFM) microscopy and contact angle measurements. The addition of PAN in the casting solution produced significant changes in the membrane structure, from finger-like porous structures to sponge-like porous structures. Increased PAN concentration in the membrane composition enhanced the hydrophilicity of the membrane surface, which also accounted for the improvement in the antifouling capabilities. The permeation of apple pomace extract and the content of polyphenols and flavonoids were used to evaluate the efficacy of the hybrid membranes created. The results showed that the hybrid nanofiltration membranes based on PPEES/PAN/PVP/SBA-15: 15/5/1/1 and 17/3/1/1 exposed to laser for 5 min present a higher rejection coefficient to total polyphenols (78.6 +/- 0.7% and 97.8 +/- 0.9%, respectively) and flavonoids (28.7 +/- 0.2% and 50.3 +/- 0.4%, respectively) and are substantially better than a commercial membrane with MWCO 1000 Da or PPEES-PVP-based membrane.

Abstract

Antibiotics are antibacterial agents applied in human and veterinary medicine. They are also employed to stimulate the growth of food-producing animals. Despite their benefits, the uncontrolled use of antibiotics results in serious problems, and therefore their concentration levels in different foods as well as in environmental samples were regulated. As a consequence, there is an increasing demand for the development of sensitive and selective analytical tools for antibiotic reliable and rapid detection. These requirements are accomplished by the combination of simple, cost-effective and affordable electroanalytical methods with molecularly imprinted polymers (MIPs) with high recognition specificity, based on their lock and key working principle, used to modify the electrode surface, which is the heart of any electrochemical device. This review presents a comprehensive overview of MIP-modified carbon-based electrodes developed in recent years for antibiotic detection. The MIP preparation and electrode modification procedures, along with the performance characteristics of sensors and analytical methods, as well as the applications for the antibiotics' quantification from different matrices (pharmaceutical, biological, food and environmental samples), are discussed. The information provided by this review can inspire researchers to go deeper into the field of MIP-modified sensors and to develop efficient means for reliable antibiotic determination.

Abstract

Few biosensors are reported for usage in combination with the organic solvent due to their negative impact on the enzymes. The usage of ternary water–organic solvent mixtures in combination with acetylcholinesterase biosensors allows to increase the useable total content of organic solvents with minimum negative effects to a higher content in comparison with a single organic solvent in water. The combination of acetonitrile/ethanol/water has a smaller negative effect on both enzyme activity and inhibition by insecticides in comparison with acetonitrile/methanol/water mixtures. The insecticides were eluted from solid-phase extraction (SPE) columns with a binary mixture of organic solvents acetonitrile/ethanol in 1/3 ratio and subsequently analysed with an acetylcholinesterase biosensor and the optimum total content of organic solvents of 12%. The analytical method allows the analysis of complex samples with improved selectivity and at improved limits of detection for chlorpyrifos-oxon and carbofuran analysis in river waters and soil samples. The usage of mixtures of organic solvents in combination with enzymes is an interesting approach that allows working with a higher total content of organic solvents than each individual solvent. © 2022 Elsevier Inc.

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Phenyl aldehyde layers were formed on copper foils by electro-assisted diazonium reactions and subsequently functionalized with either amino-2-propanol or 2-amino-1-butanol. The anticorrosion properties of the two obtained organic films 2-[(phenylmethylidene)amino]butan-1-ol and (phenylmethylidene)amino-propan-2-ol were evaluated in aerated buffer acetate solution pH = 3.5. The electrochemical corrosion inhibition properties were investigated after different immersion times using electrochemical impedance spectroscopy and potentiodynamic polarization analysis (Tafel). Contact angle measurement confirms the hydrophobic nature of the new organic coatings and layer stability after immersion in buffer. The results showed that both developed layers provided good anticorrosion protection and the highest inhibition was achieved using 2-[(phenylmethylidene)amino]butan-1-ol coating on copper, which makes it a useful device for anticorrosion protection. Moreover, correlations between the molecular structures of the corrosion inhibitors and their protecting efficiencies have been established.

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A rapid, simple, and precise electrochemical method was developed for the determination of the total content of antibiotics containing a 5-nitrofuran ring with antibacterial activity including furazolidone, nitrofurazone, nitrofurantoin, and furaltadone in several samples. Boron-doped diamond electrode was used as the working electrode. The electrochemical properties of these compounds were evaluated by cyclic voltammetry. A differential pulse voltammetric method based on the cathodic reduction at high potentials was used for the determination of the total nitrofuran content in a mixture at pH 6.47. The voltammetric measurements showed that the proposed electrochemical method was able to identify the nitrofurazone from a mixture of antibiotics based on its anodic oxidation in alkaline medium (pH 10.6). This method presented good accuracy (between 94.5 and 102.5%) and precision (less than 3.94%), with calibration graphs starting from 50 nmol L-1. The method was applied with success for the determination of total content of compounds with 5-nitrofuran ring and for the selective determination of nitrofurazone in pharmaceutical tablets and food products (milk and honey) without pretreatment of the samples.

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The nanofiltration composite membranes were obtained by incorporation of KIT-6 ordered mesoporous silica, before and after its functionalization with amine groups, into polyphenylene-ether-ether-sulfone (PPEES) matrix. The incorporation of silica nanoparticles into PPEES polymer matrix was evidenced by FTIR and UV-VIS spectroscopy. SEM images of the membranes cross-section and their surface topology, evidenced by AFM, showed a low effect of KIT-6 silica nanoparticles loading and functionalization. The performances of the obtained membranes were appraised in permeation of Chaenomeles japonica fruit extracts and the selective separation of phenolic acids and flavonoids. The obtained results proved that the PPEES with functionalized KIT-6 nanofiltration membrane, we have prepared, is suitable for the polyphenolic compound's concentration from the natural extracts.

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This study investigated the potential of using the changes in polyphenol composition of red wine to enable a more comprehensive chemometric differentiation and suitable identification of authentication markers. Based on high performance liquid chromatography-mass spectrometry (HPLC-MS) data collected from Feteasca Neagra, Merlot, and Cabernet Sauvignon finished wines, phenolic profiles of relevant classes were investigated immediately after vinification (Stage 1), after three months (Stage 2) and six months (Stage 3) of storage, respectively. The data were subjected to multivariate analysis, and resulted in an initial vintage differentiation by principal component analysis (PCA), and variety grouping by canonical discriminant analysis (CDA). Based on polyphenol common biosynthesis route and on the PCA correlation matrix, additional descriptors were investigated. We observed that the inclusion of specific compositional ratios into the data matrix allowed for improved sample differentiation. We obtained simultaneous discrimination according to the considered oenological factors (variety, vintage, and geographical origin) as well as the respective clustering applied during the storage period. Subsequently, further discriminatory investigations to assign wine samples to their corresponding classes relied on partial least squares-discriminant analysis (PLS-DA); the classification models confirmed the clustering initially obtained by PCA. The benefits of the presented fingerprinting approach might justify its selection and warrant its potential as an applicable tool with improved authentication capabilities in red wines.

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Cancer is a multifactorial disease involving reprogramming of the gene function in normal cells through both genetic and epigenetic factors. The latter ones are essentially represented by chromatin remodeling factors as transcriptional control of gene expression at the nucleus level. Certain sets of tumor suppression genes controlling vital cell functions such as cell cycle, DNA repair, cell adhesion, and apoptosis are considered candidate genes for defining specific types of cancer. Their silencing may be achieved through somatic mutations or by epigenetic factors as DNA methylation and histone covalent modification. Two major DNA methylation patterns have been described in mammary gland tumors: genome hypomethylation and concomitant in situ hypermethylation in critical genes. Human mammary gland cancer has been studied through animal models, canine one offering opportunity to investigate the molecular aspects that better define the borderline between the primary inflammatory and tumor progression processes. In contrast, both humans and dogs share the same challenging environment. This work presents the preliminary results in a study of the transcriptional epigenetic markers identified in canine mammary glands during tumor development. Bisulfite mutagenesis based methylation-specific (MS)- PCR has been performed for the estimation of BRCA1, and BRCA2 gene promoter hyper-methylation profiles, concomitant to methylation sensible restriction of genomic DNA in order to estimate the global hypo-methylation status have been performed on 9 DNA samples obtained from clinically selected canine tumor tissues. Histone H3K9 trimethylated was stained by immunohistochemical methods (IHC) in normal and tumor tissues. The results are discussed through their crosstalk with DNA methylation dynamics in order to highlight the cancer initiation and progression processes in the context of heritability and the causes of sporadic cases.

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Phenyl aldehyde layers were formed on copper foils by electro-assisted diazonium reactions and subsequently functionalized with either amino-2-propanol or 2-amino-1-butanol. The anticorrosion properties of the two obtained organic films 2-[(phenylmethylidene)amino]butan-1-ol and (phenylmethylidene)amino-propan-2-ol were evaluated in aerated buffer acetate solution pH Æ 3.5. The electrochemical corrosion inhibition properties were investigated after different immersion times using electrochemical impedance spectroscopy and potentiodynamic polarization analysis (Tafel). Contact angle measurement confirms the hydrophobic nature of the new organic coatings and layer stability after immersion in buffer. The results showed that both developed layers provided good anticorrosion protection and the highest inhibition was achieved using 2-[(phenylmethylidene)amino]butan-1-ol coating on copper, which makes it a useful device for anticorrosion protection.Moreover, correlations between the molecular structures of the corrosion inhibitors and their protecting efficiencies have been established. © 2021 Elsevier Masson SAS. All rights reserved.

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Due to the increase of the incidence of type II diabetes nowadays there are attempts to find phytotherapeutic alternatives for the prophylaxis of this disease by inhibiting the enzymes involved in glucose uptake. Thus, in this study the α-amylase and α-glucosidase inhibitory activities of some hydroalcoholic Apium graveolens and Agropyrum repens extracts (50% EtOH, v/v, 10% weight) were analysed. Extracts were processed by membranare processes, microand ultrafiltration for obtaining rich-polyphenolic extracts. The polyphenols and flavones content and antioxidant activity of them were analysed. The extracts of both plants have shown inhibitory activities on the two digestive enzymes. © 2019 Editura Academiei Romane. All rights reserved.

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Phenyl aldehyde layers were formed on copper foils by electro-assisted diazonium reactions and subsequently functionalized with either amino-2-propanol or 2-amino-1-butanol. The anticorrosion properties of the two obtained organic films 2-[(phenylmethylidene)amino]butan-1-ol and (phenylmethylidene)amino-propan-2-ol were evaluated in aerated buffer acetate solution pH Æ 3.5. The electrochemical corrosion inhibition properties were investigated after different immersion times using electrochemical impedance spectroscopy and potentiodynamic polarization analysis (Tafel). Contact angle measurement confirms the hydrophobic nature of the new organic coatings and layer stability after immersion in buffer. The results showed that both developed layers provided good anticorrosion protection and the highest inhibition was achieved using 2-[(phenylmethylidene)amino]butan-1-ol coating on copper, which makes it a useful device for anticorrosion protection.Moreover, correlations between the molecular structures of the corrosion inhibitors and their protecting efficiencies have been established. © 2021 Elsevier Masson SAS. All rights reserved.

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This study was focused on the phytochemical composition and biological activities of Anchusa officinalis and Melilotus officinalis polyphenolic-rich extracts obtained by nanofiltration. The high-performance liquid chromatography-mass spectrometry analysis showed that chlorogenic acid and rosmarinic acid were the main phenolic acids in both extracts. The main flavonoid compound from A. officinalis extracts is luteolin, whereas rutin and isoquercitrin are the main flavonoids in M. officinalis. M. officinalis polyphenolic-rich extract had the highest alpha-amylase (from hog pancreas) inhibitory activity (IC50 = 1.30 +/- 0.06 mu g/mL) and alpha-glucosidase (from Saccharomyces cerevisiae) inhibitory activity (IC50 = 92.18 +/- 1.92 mu g/mL). However, both extracts presented a significant alpha-glucosidase inhibitory activity. Furthermore, the hyaluronidase inhibition of polyphenolic-rich extracts also proved to be stronger (IC50 = 11.8 +/- 0.1 mu g/mL for M. officinalis and 36.5 +/- 0.2 mu g/mL for A. officinalis), but there was moderate or low lipoxygenase inhibition. The studies on the fibroblast cell line demonstrated that both A. officinalis and M. officinalis polyphenolic-rich extracts possess the cytotoxic effect at a concentration higher than 500 mu g/mL. The experimental data suggest that both extracts are promising candidates for the development of natural antidiabetic and anti-inflammatory food supplements.

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Because melatonin has strong antioxidant activity and wine is an alcoholic beverage of economic relevance, in the present work, the impact of some variable parameters that may occur in the winemaking process on the concentrations of melatonin and its precursors in Romanian wines was studied. Therefore, a sensitive and selective high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the simultaneous analysis of melatonin, serotonin, and L-tryptophan, and some method performance parameters including selectivity, detection limit, precision (by comparing with an alternative HPLC-FL method), accuracy, and robustness were validated. These determinations are significant and the final amounts of analytes are dependent on the microorganisms involved in the winemaking process, the grape variety, geographic regions of vineyards, and aging of wines. In the future, the method may be useful to increase the melatonin content and the antioxidant activity in wines by improved steps in the winemaking process, especially based on application of selected yeasts and improved fermentation conditions.

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Since early times, various plants have been used as remedies for treating different kinds of diseases and lesions with satisfying results. The phenolic compounds are secondary metabolites from medicinal plants which include a wide category of compounds such as phenolic acids, flavonoids, tannins, stilbenes, curcuminoids, xanthones, coumarins, lignans, etc. Between these, lignans are considered important in cancer prevention and treatment, besides other beneficial health effects, e.g. antioxidant, anticarcinogenic, antimutagenic, and anti-estrogenic effects. This review summarizes the most recent literature and the most important results concerning plant lignans and their derivatives in cancer prevention and treatment, both in vitro and in vivo assessments. The mechanistic aspects will be also highlighted.

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The tendency of using herbs extracts or natural compounds extracted from herbs for preventing or treating different illnesses, including cancer, continues to be an alternative to drug use. Many studies of plant compounds aimed at finding substances with selective cytotoxicity on abnormal cells. Phenolic compounds, as important secondary metabolites from plants, are one of them. In this review, the recent literature data from the past five years about anticancer/antitumor effect of flavonoids and tannins extracted from medicinal plants are surveyed. The cytostatic/antitumor effects of the individual compounds extracted from plants and/or of the plants' polyphenolic extracts are considered, in order to point out the most significant constituents or plants with anticancer potential. The most important results concerning these compounds and their derivatives in cancer prevention and treatment, the importance of their chemical structure, their mechanism of action in vitro and in vivo, and some bioavailability aspects are discussed.

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Because melatonin has strong antioxidant activity and wine is an alcoholic beverage of economic relevance, in the present work, the impact of some variable parameters that may occur in the winemaking process on the concentrations of melatonin and its precursors in Romanian wines was studied. Therefore, a sensitive and selective high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the simultaneous analysis of melatonin, serotonin, and L-tryptophan, and some method performance parameters including selectivity, detection limit, precision (by comparing with an alternative HPLC-FL method), accuracy, and robustness were validated. These determinations are significant and the final amounts of analytes are dependent on the microorganisms involved in the winemaking process, the grape variety, geographic regions of vineyards, and aging of wines. In the future, the method may be useful to increase the melatonin content and the antioxidant activity in wines by improved steps in the winemaking process, especially based on application of selected yeasts and improved fermentation conditions. © 2020 American Chemical Society

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The tendency of using herbs extracts or natural compounds extracted from herbs for preventing or treating different illnesses, including cancer, continues to be an alternative to drug use. Many studies of plant compounds aimed at finding substances with selective cytotoxicity on abnormal cells. Phenolic compounds, as important secondary metabolites from plants, are one of them. In this review, the recent literature data from the past five years about anticancer/antitumor effect of flavonoids and tannins extracted from medicinal plants are surveyed. The cytostatic/antitumor effects of the individual compounds extracted from plants and/or of the plants' polyphenolic extracts are considered, in order to point out the most significant constituents or plants with anticancer potential. The most important results concerning these compounds and their derivatives in cancer prevention and treatment, the importance of their chemical structure, their mechanism of action in vitro and in vivo, and some bioavailability aspects are discussed. © 2020 Bentham Science Publishers.

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A stable and reproducible layer of Prussian blue (PB) modified with copper was electrodeposited on carbon paper electrodes for the multiple detection of ester flavorants with a bienzymatic biosensor. Carbon fiber composite paper was investigated as high-surface, low-cost substrate for biosensor development. The pre-activation of the electrode surface by cyclic voltammetry was necessary to improve the electrochemical properties before the electrochemical deposition of Prussian blue-copper film (PB-Cu). The stability and the reproducibility of the obtained PB-Cu carbon paper electrode was demonstrated at pH 7.4, optimum for biosensor development. The developed biosensor is based on the immobilization of two enzymes (carboxyl esterase and alcohol oxidase) by cross-linking with glutaraldehyde onto PB-Cu carbon paper electrode. A mixture of key aroma ester compounds (methyl butyrate, ethyl butyrate, methyl cinnamate and ethyl cinnamate) was detected in several food samples with low interferences.

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This study evaluated the biological activities of Eryngium planum and of Cnicus benedictus extracts enriched in polyphenols obtained by nanofiltration. The HPLC-MS analysis showed that E. planum contains mainly flavonoids, especially rutin, while in C. benedictus extracts show the high concentration of the phenolic acids, principally the chlorogenic acid and sinapic acid. Herein, there is the first report of ursolic acid, genistin, and isorhamnetin in E. planum and C. benedictus. C. benedictus polyphenolic-rich extract showed high scavenging activity (IC50=0.0081 mg/mL) comparable to that of standard compound (ascorbic acid) and a higher reducing power (IC50= 0.082 mg/mL), with IC50 having a significantly lower value than IC50 for ascorbic acid. Both extracts were nontoxic to NCTC cell line. Among the investigated herbs, E. planum polyphenolic-rich extract showed the highest inhibitory activities with the IC50 value of 31.3 g/mL for lipoxygenase and 24.6 g/mL for hyaluronidase. Both polyphenolic-rich extracts had a higher inhibitory effect on -amylase and -glucosidase than that of the acarbose. The synergistic effect of ursolic acid, rutin, chlorogenic acid, rosmarinic acid, genistin, and daidzein identified in polyphenolic-rich extracts could be mainly responsible for the pharmacological potentials of the studied extracts used in managing inflammation and diabetes.

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In this work we aimed to examine the influence of the main abiotic factors (temperature, rainfall, relative humidity, atmospheric pressure) on the synthesis of active compounds (phenolics, flavonoids), with antioxidant and therapeutic effect of two herbs - Capsella bursa-pastoris (shepherd's purse) and Marrubium vulgare (horehound) collected from two different areas of Romania: Dobrogea (Constanta) and Muntenia (Bucharest). The studies have shown that biogenesis and accumulation of secondary metabolites that gives the therapeutic properties of medicinal plants is influenced by biotic and abiotic factors. In this work we aimed to determine the profile of concentrations of biologically active compounds from the studied herbs depending on the harvest time period and variability of the environmental factors. The medicinal herbs had harvested in autumn (September, 2013) and in spring (May – June, 2014); the alcoholic and aqueous extracts were analyzed in terms of composition: In main biologically active compounds (phenolics, flavonoids) and antioxidant activity as DPPH and ABTS, and spectral data analysis by FTIR. Experimental data obtained showed a significantly higher phenolics and flavonoids content and also a higher antioxidant activity in herbs harvested from the Dobrogea (Constanta) area, for the herbs studied. © 2019, Gheorghe Asachi Technical University of Iasi, Romania. All rights reserved.

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Acrylamide (AA) is a toxic compound formed in thermally prepared foods by Maillard reaction. Besides foods, AA may be found in cosmetic products as an impurity of the widely-used non-toxic polyacrylamide. We present a novel, fast and selective detection method based on the amperometric monitoring of the coupling reaction between reduced glutathione (GSH) and AA catalyzed by glutathione S-transferase (GST) to produce an electrochemically inactive compound. We have used electrodes modified with cobalt-phthalocyanine to monitor the decrease of GHS concentration at +300 mV. Our system is simple, does not require supplementary substrates such as 1-chloro-2,4-dinitrobenzene (CDNB) nor have disadvantageous competitive kinetics characteristic to inhibition like signals. Using the optimum concentration of 100 M GSH we have obtained a linear calibration graph from 7 to 50 M AA and a limit of detection of 5 M AA. The method is not affected by interfering compounds usually found in foods and was applied for real sample analysis.

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It is well known that the secretion of melatonin begins after the first months of life and is necessary to be supplied through mother's milk or infant formula. It is also important to know the concentrations of compounds involved in the synthesis of melatonin in the pineal gland from the composition of infant formula. Therefore, an HPLC method with UV and fluorescence detection was developed which enables the simultaneous determination of melatonin, serotonin, L-tryptophan, and vitamins B-3 and B-6 in 30 min. The chromatographic method was validated in terms of selectivity, linearity range of the response (R > 0.9997), detection limit (0.0011-0.01 mg L-1), limit of quantitation, precision, accuracy, and robustness and has been proved that it may be used as a tool for evaluating these compounds in infant formulas and also in the manufacture of baby foods. The chromatographic method was applied for the quantification of analytes of interest and for the first time, it has proven the existence of melatonin (0.00045-0.00824 mg/g) and serotonin (0.00002-0.00056 mg/g) in infant formulas from birth onwards.

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Background: In the last years, the production and applications of nanoparticles based on iron oxides in the field of biomedicine presented a great interest due to their particular properties. Because of the expansion of the pharmaceutical industry numerous new systems for drugs delivery have appeared, and those centered on magnetic nanoparticles are in a particular attention and in different promising developmental stages. Objective: In this mini review, some representative, interesting and feasible magnetic nanostructures obtained recently (from last 5-6 years) with possible use in antitumor/anticancer therapy are presented. Results: The synthesis of these nanostructures with magnetic properties implies very simple assembling procedures and presents one of the lowest cytotoxic profiles. Magnetic nanostructures displayed possible appliance in a large diversity of biotechnological and medical fields, both for diagnose and therapy. Conclusion: Different types of magnetic nano-carriers loaded with different antitumor/ anticancer agents and the cases tested in vivo are considered.

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This work presents the efficacy of various green extraction methods used to ensure the optimal amount of antioxidant compounds extracted from vegetal material. The new developed extraction procedures are easy-to-use and have a low implementation cost providing health-safe and high-quality extracts (products). The complete characterization of the obtained extracts was performed by a HPLC method (quantification of antioxidant compounds) and the ORAC method (efficacy assessment). These methodologies have high potential in by-products industry, where managing the residues is an important step in increasing the technological process economic efficiency and mitigation of environmental impact and, moreover, can by further extended to other types of raw materials.

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Berteroa incana is a wild herb widespread in temperate zones which was practically not studied for its biological effects. Methanolic and aqueous extracts of B. incana were assessed for the content in polyphenols and the related antioxidant and antimicrobial activities and the polysaccharide extract for the content in saccharides and the associated cytostatic effect. The results obtained highlighted that the methanolic extracts of B. incana contain moderate amounts of polyphenols, the most representative been isoquercitrin 4.41 +/- 0.02 mg100 g(-1)dry weight plant material (DW), quercetin 4.21 +/- 0.05, sinapic acid 5.23 +/- 0.12 and ferulic acid 5.05 +/- 0.12 mg 100 g(-1)DW, with correlated moderate antioxidant activities (IC (50) 13.40 +/- 0.01 mu g mL(-1)) and absent antibacterial activity. The polysaccharide fraction showed high content in saccharides, especially in arabinose (312.22 +/- 7.54 mg g(-1) polysaccharide extract) and glucose (279.22 +/- 5.59), and promising cytostatic effect. [GRAPHICS] .

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In this study several investigations and tests were performed to determine the antioxidant activity and the acetylcholinesterase and tyrosinase inhibitory potential of Pulmonaria officinalis and Centarium umbellatum aqueous extracts (10% mass) and ethanolic extracts (10% mass and 70% ethanol), respectively. Moreover, for each type of the prepared extracts of P. officinalis and of C. umbellatum the content in the biologically active compounds – polyphenols, flavones and proanthocyanidins was determined. The antioxidant activity was assessed using two methods, namely the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and reducing power assay. The analyzed plant extracts showed a high acetylcholinesterase and tyrosinase inhibitory activity in the range of 72.24–94.24% (at the highest used dose – 3 mg/mL), 66.96% and 94.03% (at 3 mg/mL), respectively correlated with a high DPPH radical inhibition – 70.29–84.9% (at 3 mg/mL). These medicinal plants could provide a potential natural source of bioactive compounds and could be beneficial to the human health, especially in the neurodegenerative disorders and as sources of natural antioxidants in food industry. © 2016

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A 120 kilometers reach of the Prut River, Romania was surveyed and the concentrations of four trace metals (copper, cadmium, lead and zinc) were determined in water and sediments. These elements are the main pollutants expected in the region, as a steel-producing factory in Romania is located in the close neighborhood of an area under protection, the Lower Prut Floodplain Natural Park. Samples were collected in 2010 and 2011 from the water-sediment interface at six locations along the lower sector of the Prut River. Sediments were sampled only once whereas water samples were collected during four campaigns organized at the end of the summer and beginning of the autumn in order to include both high and low flow regimes of the river. Toxic metals (Pb and Cd) were not found to reach notable levels. The resulted concentrations for all trace metals were lower than the values determined in other Romanian rivers (e.g. Danube) and within the values range imposed by the Romanian regulations for water and sediments quality. © 2018, Gheorghe Asachi Technical University of Iasi, Romania. All rights reserved.

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Acrylamide (AA) is a toxic compound formed in thermally prepared foods by Maillard reaction. Besides foods, AA may be found in cosmetic products as an impurity of the widely-used non-toxic polyacrylamide. We present a novel, fast and selective detection method based on the amperometric monitoring of the coupling reaction between reduced glutathione (GSH) and AA catalyzed by glutathione S-transferase (GST) to produce an electrochemically inactive compound. We have used electrodes modified with cobalt-phthalocyanine to monitor the decrease of GHS concentration at +300 mV. Our system is simple, does not require supplementary substrates such as 1-chloro-2,4-dinitrobenzene (CDNB) nor have disadvantageous competitive kinetics characteristic to inhibition like signals. Using the optimum concentration of 100 μM GSH we have obtained a linear calibration graph from 7 to 50 μM AA and a limit of detection of 5 μM AA. The method is not affected by interfering compounds usually found in foods and was applied for real sample analysis. © 2018 The Royal Society of Chemistry.

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Copper substrates deposed on a gold screen-printed electrodewere coveredwith different aryl diazonium salts by electrodeposition at 0.25 mA for 30 or 300 s. Seven compounds were investigated: 4-aminophenylacetic acid, 4-aminophenethyl alcohol, 4-fluoroaniline, 4-(heptadecafluorooctyl) aniline, 4-aminoantipyrine, 4-(4-aminophenyl) butyric acid and 3,4,5-trimethoxyaniline. Quantitative monitoring of the electrodeposition process was carried out by electrogravimetry using quartz crystal microbalance (QCM). The electrodeposited mass varies between 26 ng/cm(2) for 4-fluoroaniline formed during 30 s to 442 ng/cm(2) for 4-phenylbutyric acid formed during 300 s. The corrosion inhibition properties of aryl-modified layers have been studied in buffer citrate with pH = 3 or 3.5% NaCl solutions using electrochemical noise (ECN) and Tafel potentiodynamic polarization measurements. A corrosion inhibiting efficiency up to 90% was found. The highest corrosion inhibition was obtained for 4-(4-aminophenyl) butyric acid and the lowest for 4-fluoroaniline. A relation between the inhibition efficiency and the chemical nature of the substituents in the protective layer was found.

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The goal of the present work was to study the influence of winemaking procedures and the effect of bottle-aging on the antioxidant activity and on the variation of low molecular weight phenolics of Feteasca Neagra and Negru Aromat red wine from the Valea Calugareasca vineyard, Romania. The free radical-scavenging activity was measured using the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical from bottles sampled every 3 months up to the 9th month. The results indicated that Negru Aromat obtained by classical maceration had the highest activity at 6th month. The highperformance liquid chromatography results showed that the most abundant low molecular weight phenolic compounds were catechin, (-)-epicatechin, gallic acid, malvidin, and peonidin 3-O-glucoside. For the phenolics, Feteasca Neagra prepared by classical maceration and Negru Aromat by run-off juice were the richest. For anthocyanidins, the Feteasca Neagra and Negru Aromat wine by classical maceration had the highest concentrations. These results suggest that classical maceration is the winemaking procedure of choice to obtain the highest quality wine from the Valea Calugareasca vineyard.

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In the present study the antioxidant and cytostatic capacities of some 8% Geranium robertianum (geranium) aqueous extracts processed by membrane procedures (micro- and ultrafiltration) were determined. The extracts were purified by microfiltration and then concentrated by successive ultrafiltrations using Millipore membranes with 10,000 and 1000 Da cut-off. Two methods were used to establish the extracts' antioxidant activity: DPPH and ABTS; the cytostatic capacity was evaluated on HEp-2p cell lines, by a qualitative method (cytochemical stain with Giemsa solution) and quantitative one (MTT test). Four concentrations of Geranium aqueous extracts were used to test cell viability: 100, 500, 1000 and 2000 mu g/mL, 24 and 48 h, against the control culture (100% viability). The concentrated samples had the highest content of total polyphenols and the strongest antioxidant effect, having also the biggest impact upon cell viability. (C) 2013 Production and hosting by Elsevier B.V. on behalf of King Saud University.

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A fast separation method for simultaneous determination of eleven organic acids was validated and applied to different commercial food items to evaluate their organic acids content. The present method gives detection limits between 0.04 and 4.65 mu g mL(-1), recovery values in real samples between 78.2 and 97.3% and relative standard deviation values for precision lower than 5%. All validation data were in acceptable range and prove the method's fit for purpose. The advantages of the method are the short runtime analysis (15 min), no preparation step for the samples before the injection combined with good sensitivity which recommends it for routine control analysis in food industries. Moreover, this methodology has high potential in drinks industry but can by further extended to other types of food items.

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Novel molecularly imprinted polymers (MIPs) designated for the solid-phase extraction of antibiotics containing a 5-nitrofuran ring (nitrofurantoin and furaltadone) are reported. The synthesis of these MIPs was based on commercial monomers and cross-linking agents capable of forming hydrogen bonds with the template molecules. Thus, the designed MIPs should involve acceptable costs and easier accessibility. Their retention properties were studied by solid-phase extraction (SPE) procedures and the breakthrough curves were evaluated for both imprinted and non-imprinted polymers (NIPs). Due to the presence of adsorption sites created in polymers by imprinting, the MIPs showed a significant difference in the retention property in comparison to NIPs. The MIPs were also immobilized onto a gold electrode surface by entrapment into a silane sol-gel matrix for the development of a sensor based on electrochemical impedance measurements. The good mechanical adherence of the sol-gel matrix on the gold electrode surface was achieved by formation of a self-assembled monolayer using 3-mercaptopropyl trimethoxisilane that acts as an anchoring bridge.

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Portulaca pilosa L and Portulaca oleracea L were comparatively studied for the total content of polyphenols and flavonoids, antioxidant activity, individual polyphenols, short-chain organic acids, and saccharides in extracts of plants collected from Bucharest ''delta'' using spectrometry and capillary electrophoresis. The polysaccharide fractions were assessed for cytotoxicity on normal and tumor cell lines. The results obtained highlighted that Portulaca pilosa could be considered more valuable than Portulaca oleracea because of its higher content in important flavonoids (quercetin 101.70 +/- 2.68 mu g g(-1) dry weight plant material, rutin 96.24 +/- 0.74 mu g g(-1) DW plant material) and some phenolic acids (chlorogenic acid 161.33 +/- 0.67 mu g g(-1) DW plant material, p-coumaric acid 61.40 +/- 5.50 mu g g(-1) DW plant material) of the ethanolic extracts, for its lower content in oxalic acid that is considered anti-nutrient of the aqueous extracts, and for its higher content in saccharides, especially rhamnose and xylose, with consequently higher cytostatic effect of the polysaccharide fraction. The current study presented for the first time the content in polyphenols, short chain organic acids, and saccharides of Portulaca pilosa and proved that this species has noticeable antioxidant activity, low toxicity on normal cells, and high toxicity on tumor cells and could be considered important for health and food industry.

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Some aspects of the chemical composition were studied in extracts of unexplored Phemeranthus confertiflorus L, an alien plant collected from Bucharest delta. 16 polyphenols and 10 short-chain organic acids were analysed and quantified by capillary electrophoresis in Phemeranthus extracts and antioxidant activity was investigated. The results obtained could promote Phemeranthus as an eligible plant with potential in food industry and for human health, because of the high antioxidant activity, high content of flavonoids (naringenin, rutin, daidzin) and lactic acid.

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The objectives of this study were to define the phenolic profile, antioxidant, antimicrobial and anti-inflammatory properties of extracts from Betonica officinalis and Salvia officinalis herbs used in traditional medicine. The results indicated that the extract inhibits scavenges stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radicals. In the present study, Salvia officinalis was potent antibacterial agent against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The extracts inhibited cyclooxygenase (COX-1) and denaturation of protein, which suggests these species might be a potential source of plant-derived anti-inflammatory substances. Our study, for the first time, revealed the antimicrobial and anti-inflammatory activity of the Betonica officinalis herb. The results of this study could be helpful to develop medicinal preparations and uses of this species as an antimicrobial, anti-inflammatory and wound healing agent.

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A low-interferences enzymatic sensor for evaluating the antioxidant capacity was developed. Xanthine oxidase was used to produce superoxide radicals that spontaneously dismutate to hydrogen peroxide. Low xanthine concentrations were used to minimize the rapid dismutation of the superoxide radical before its fast reaction with antioxidants. The sensor operates in the reduction mode, and evaluations with low interferences of the antioxidant capacity are based on the detection of remaining hydrogen peroxide using Prussian blue electrodes at low potentials. The linear calibration graph is between 2 - 10 mu M ascorbic acid. No interferences were observed from easily oxidisable substances including uric acid, which is produced in the enzymatic reaction or other substances usually found in foods. The method was used to evaluate the antioxidant capacity in different real juice samples.

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Prussian blue modified with copper was electrodeposited on a platinum microelectrode for the amperometric determination of hydrogen peroxide at -50 mV. The Prussian blue-copper layer was stable for 2 h at pH 7.4 and a storage period of 2 months. The Prussian blue-copper modified microelectrodes were used to develop oxidase based microbiosensors for ethanol and lactate. Lactate and alcohol oxidases were immobilized by cross-linking with glutaraldehyde. No interferences were observed from possible interfering compounds up to a concentration of 0.5 mM. The calibration plot of the lactate microbiosensor was linear between 0.005 and 0.2 mM with a limit of detection of 0.0035 mM lactate. The linear dynamic range of the alcohol microbiosensor was between 0.05 and 2 mM and the limit of detection was 0.02 mM ethanol. The developed microbiosensors were used for the analysis of pickled cucumber juice, yogurt, and wine.

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The quality of red wines is given by phenolic compounds and anthocyanins and is associated with colour, taste and therapeutic effects on human health. This work aims to provide a detailed profile of phenolic compounds and anthocyanins that are found in five red wine samples from Dealu Mare-Valea Calugareasca region. The phenolic and anthocyanin profiles of the red wine samples were determined by high-performance liquid chromatography-photodiode array-mass spectrometry and matrix-assisted laser desorption/ionisation-time of flight, respectively. The results obtained showed that Feteasca Neagra had the highest content of phenolic compounds followed by Pinot Noir while the preponderant compound was gallic acid. Amongst anthocyanins, malvidin was found to be the major compound and the highest anthocyanin content was found also for Feteasca Neagra wine. A simple high-performance liquid chromatography-photodiode array-mass spectrometry method was developed, optimised and applied for the quantification of phenolic compounds in red wine samples from Dealu Mare-Valea Calugareasca region. In the same time, a rapid matrix-assisted laser desorption/ionisation-time of flight method that does not need sample preparation was applied for the identification of anthocyanins. Moreover, the phenolic and anthocyanin composition of red wines from Dealu Mare-Valea Calugareasca region is reported for the first time. The phenolic and anthocyanin profile determination will be beneficial for the Romanian winemakers to produce high-quality red wines.

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In the current work, ethanol and water extracts of Verbascum phlomoides and Solidago virgaureae were examined for their inhibitory effects against acetylcholinesterase and tyrosinase, as well as for their antioxidant activity. The antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and a reducing power assay. The total content of phenolics, flavonoids and proanthocyanidins, and the high-performance liquid chromatography profile of the main phenolic compounds were also determined. Generally, ethanol extracts showed the strongest antioxidant and enzyme inhibitory activities, both of which were related to the total phenolic content. The V. phlomoides ethanol extract showed the highest inhibitory activity against both acetylcholinesterase (IC50= 0.086 +/- 0.005 mg/mL) and tyrosinase (IC50= 0.109 +/- 0.092 mg/mL). These results reveal that V. phlomoides and S. virgaureae are potential sources of active metabolites with acetylcholinesterase and tyrosinase inhibitory effects. As a result they could be considered for dietary food supplements for preventing neurodegenerative diseases. (C) 2016 Elsevier GmbH. All rights reserved.

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The aim of this study was to investigate the antioxidant, anti-amylase and anti-glucosidase activities of polyphenolic-rich extracts from Betonica officinalis and Impatiens noli-tangere and to analyze their chemical composition by HPLC-MS. Hydro-alcoholic extracts of the two medicinal herbs were processed by microfiltration and ultrafiltration for concentrating the polyphenolic compounds. Phenolic acid, mainly chlorogenic acid and caffeic acid were the dominant compounds of B. officinalis extracts, while the extracts from L nolitangere contain mainly flavonoids, especially isoquercitrin. The polyphenolic-rich extract (retentate UF fraction) from B. officinalis exhibited the most potent DPPH radical scavenging and reducing power activities. The IC50 value of the alpha-amylase inhibitory effect was 4.20 +/- 0.30 mg/mL for the B. officinalis polyphenolic-rich extract, slightly higher than that of I. noli-tangere polyphenolic-rich extract of 4.01 +/- 0.25 mg/mL. The polyphenolic-rich extract from I. noli-tangere showed remarkable a-glucosidase inhibition activity (IC50 0.47 +/- 0.02 mg/mL), compared to the acarbose (IC50 0.38 +/- 0.02 mg/mL). However, I. noli-tangere extracts displayed a stronger inhibitory activity than B. officinalis extract fractions. Our study, for the first time, revealed the anti-diabetic potential of the B. officinalis and I. noli-tangere herbs. The results of this study could be helpful to develop medicinal preparations or functional foods for diabetes. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

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The electrophoretic method partially validated for separation and quantification of 16 polyphenols from aqueous and ethanolic extracts of Calendula officinalis, Hypericum perforatum, Galium verum and Origanum vulgare in 27 min showed good efficiency and precision, and low detection and quantification limits (between 0.06 - 1.38 mu g mL(-1) and 0.2 - 4.56 mu g mL(-1), respectively). Correlation coefficients (r(2)) exceed 0.994 and recovery values ranged between 86.66 and 101.54 %. Under these conditions the developed electrophoretic method would be suitable for the analysis of various extracts.

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The matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF) and micellar electrokinetic chromatography (MEKC) methods were used to identify and quantify five tannins, (+)-catechin, (-)-epigallocatechin, (-)-epigallocatechin gallate, (-)-epicatechin gallate and (-)-epicatechin, from aqueous, ethanolic and acetonic extracts of Calendula officinalis, Hypericum perforatum, Galium verum and Origanum vulgare. The MALDI-TOF technique was used for screening tannins monomers and oligomers in plant extracts. The sandwich method and matrix 2,5-dihydroxybenzoic acid with a concentration of 10 mg mL(-1) in acetonitrile/ultrapure water/trifluoroacetic acid (20 : 80 : 0.1, vol.) were used. The electrophoretic method developed for the separation and quantification of 5 catechins in 15 min exhibited good efficiency and precision, low limits of detection (0.0032-0.0153 mu g mL(-1)) and quantification (0.0096-0.0466 mu g mL(-1)). The correlation coefficients (R-2) exceeded 0.9986 and the recovery values ranged between 94.25 % and 102.50 %. The present work provides new information on some of the less studied compounds present in plants frequently used in traditional medicine. (C) 2015 Institute of Chemistry, Slovak Academy of Sciences

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A nanocomposite formed from molybdenum disulphide (MoS2) and graphene quantum dots (GQDs) was proposed as a novel and suitable support for enzyme immobilisation displaying interesting electrochemical properties. The conductivity of the carbon based screen-printed electrodes was highly improved after modification with MoS2 nanoflakes and GQDs, the nanocomposite also providing compatible matrix for laccase immobilisation. The influence of different modification steps on the final electroanalytical performances of the modified electrode were evaluated by UV-vis absorption and fluorescence spectroscopy, scanning electron microscopy, transmission electron microscopy, X ray diffraction, electrochemical impedance spectroscopy and cyclic voltammetry. The developed laccase biosensor has responded efficiently to caffeic acid over a concentration range of 038-100 mu M, had a detection limit of 0.32 mu M and a sensitivity of 17.92 nA mu M-1. The proposed analytical tool was successfully applied for the determination of total polyphenolic content from red wine samples. (C) 2015 Elsevier B.V. All rights reserved.

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beta-Carbolines are inhibitors of monoamine oxidases (MAO-A and MAO-B) and can be found in foods, hallucinogenic plant or various drugs. We have developed a fast analysis method for beta-carbolines based on the inhibition of MAO. The enzymes were immobilized on screen-printed electrodes modified with a stabilized film of Prussian blue that contain also copper. We have used benzylamine as substrate for the enzymatic reaction and the hydrogen peroxide was measured amperometrically at -50 mV. The detection limits obtained were 5.0 mu M for harmane and 2.5 mu M for both harmaline and norharmane. The MAO-A is inhibited by all three tested beta-carbolines (harmane, norharmane, and harmaline) while MAO-B is inhibited only by norharmane. The presence of norharmane in mixtures of beta-carbolines can be identified based on the difference between the cumulative inhibition of MAO-A by all beta-carbolines and MAO-B inhibition. The developed biosensors were used for food analysis. (C) 2015 Elsevier B.V. All rights reserved.

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The optimization of an aptasensor with SPR detection allowed the determination of an allergen protein, lysozyme, with high accuracy, good sensitivity and a detection limit of 2.4 nM for spiked red and white wines. The interaction of lysozyme with specific phenolic compounds from wine was evidenced by circular dichroism and SPR. Quantitative recovery factors higher than 88% for wine lysozyme were achieved based on a sample pre-treatment procedure with high concentration of sodium chloride and Tween-20. This aptasensor is useful to monitor the lysozyme levels during winemaking. Also reported is a new chromatographic method based on size exclusion that provided a good separation of lysozyme from wine components, with a detection limit of 35 nM or 0.5 mu g/mL. (C) 2014 Elsevier B.V. All rights reserved.

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In this work a novel sensor array platform based on a dual carbon screen-printed electrode was developed for the simultaneous determination of chlorogenic acid and caffeine. One of the carbon working electrodes was modified with platinum nanoparticles, reduced graphene oxide and laccase (C-SPE/Pt-NPs/RGO/lacc-biosensor) for chlorogenic acid determination and the second carbon working electrodes was modified with reduced graphene oxide and Nafion (C-SPE/RGO/Nafion-sensor) for caffeine determination. Cyclic voltammetry was used to characterise and optimise the dual sensor array while chronoamperometry was used to investigate the bioelectrocatalytic response. The C-SPE/Pt-NPs/RGO/lacc for biosensing chlorogenic acid exhibited a sensitivity of 0.02 mu A mu M (1) and a detection limit of 2.67 mu M whereas the C-SPE/RGO/Nafion used for sensing caffeine has showed a sensitivity of 1.38 mu A mu M-1 and a detection limit of 0.22 mu M. The developed sensor array was used to determine these two major coffee bean compounds from real coffee samples. Due to its simplicity, feasibility and accessibility, the developed dual sensor array could represent the basis of a valuable analytical tool able to screen both chlorogenic acid and caffeine content from coffee samples offering important information about the phytochemical composition of the samples.

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Context: Eryngium planum, Geum urbanum and Cnicus benedictus plants are an endemic botanical from the Romanian used in folk medicine. Objective: The extracts from three Romanian medicinal plants were investigated for their possible neuroprotective potential. Materials and Methods: Within this study, in vitro neuroprotective activity of the extracts of E. planum, G. urbanum, and C. benedictus plants were investigated via inhibition of acetylcholinesterase (AChE) and tyrosinase (TYR). Total content of phenolics, flavonoids, and proanthocyanidins, high-performance liquid chromatography profile of the main phenolic compounds and antioxidant activity were also determined. Results: Among the tested extracts, the best inhibition of AChE (88.76 +/- 5.2%) and TYR (88.5 +/- 5.2%) was caused by C. benedictus ethanol (EtOH) extract. The G. urbanum extracts exerted remarkable scavenging effect against 2,2-diphenyl-1-picrylhydrazyl (IC 50, 7.8 +/- 0.5 mu g/mL aqueous extract, and IC50, 1.3 +/- 0.1 mu g/mL EtOH extract, respectively) and reducing power, whereas the EtOH extract of C. benedictus showed high scavenging activity (IC 50, 0.609 +/- 0.04 mg/mL), also. Conclusion: According to our knowledge, this is the first study that demonstrates in vitro neuroprotective effects of E. planum, G. urbanum and C. benedictus.

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The main objective of this study is to concentrate the antioxidant bioactive compounds from the hydroalcoholic extract of Phyllitis scolopendrium through the poly(1,4-phenylene ether ether sulfone) (PPEES) ultrafiltration membrane. The PPEES membrane was prepared using the phase inversion method. The total content of phenolics and flavonoids, HPLC profile of the main phenolic compounds, and antioxidant and anti-tyrosinase activities were also determined in the microfiltrate, permeate and concentrate. When the PPEES membrane is used the concentration of polyphenols and flavonoids is higher, reaching the retention index of 0.785 and of 0.683, respectively, than that measured in the case of processing the feed through the PSF membrane. PPEES membranes showed a higher concentration towards anti-tyrosinase compounds (71.9 +/- 4.3%), compared with the PSF membranes (58.7 +/- 2.9%). The obtained results proved that the PPEES membrane we have prepared is suitable for the bioactive compound's concentration from the herbal extracts. This could result in their wide application in the food and pharmaceutical industries.

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Different Roumanian propolis ethanolic extracts were investigated regarding their content in total polyphenols, flavones, flavonols, flavanones and dihydroflavonols. The antioxidant activities were assessed using systems such as 1, 1-diphenyl-2-picrylhydrazyl, 2, 2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid), ferric reducing ability power and linoleic acid emulsion; the results were correlated with the concentrations in active compounds. A high performance liquid chromatography with diode array detection validated method was used for quantitation of 17 polyphenolic compounds in Roumanian propolis samples. The results confirmed that Roumanian propolis is an important sources of polyphenols and possesses a strong antioxidant activity.

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Medicinal plants represent an important source of active biological compounds that could be used for new drugs development. The present work aims the assessment of two Romanian medicinal plants that were not well studied Alchemilla vulgaris and Filipendula ulmaria with respect to their neuroprotective potentiality. The aqueous extracts (10% mass) and ethanolic extracts (10% mass and 70% (v/v) ethanol) of A. vulgaris and F. ulmaria were screened to evaluate their acetylcholinesterase and tyrosinase inhibitory effects as well as their antioxidant activity. The antioxidant activity was determined using two methods, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power assay. The total polyphenolic content determined in the tested compounds was between 88.00 and 112.33 mu g/mL, flavones between 360.00 and 862.00 mu g/mL and proanthocyanidins between 77.66 and 130.00 mu g/mL. The acetylcholinesterase inhibitory activity was determined to be between 77.03 and 98.39% (at the highest used dose -3 mg/mL), the tyrosinase inhibitory activity was found to be between 60.00 and 90.65% (at 3 mg/mL) and the DPPH radical inhibition between 73.90 and 93.49%. These findings support the use of these medicinal plants in the treatment of neurodegenerative disorders such as Parkinson, Alzheimer. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

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The present work describes the development of an electrochemical method based on the use of 2,2'-diphenyl-1-picrylhidrazyl free radical (DPPH.) for the determination of the antiradical properties of several olive oils. Differential pulse voltammetry was used as measuring technique while the electrochemical process was recorded at a platinum screen-printed working electrode. The decrease in 2,2'-diphenyl-1-picrylhidrazyl peak current intensity was measured at a specific potential value of +160 mV vs. screen-printed pseudo-reference electrode, in the presence of alpha-, delta- and gamma-tocopherol and olive oil samples, respectively. The obtained results using differential pulse voltammetry, as detection technique for real samples analysis, showed a satisfactory agreement with those obtained by high-performance liquid chromatography coupled with fluorescence detection. The reported electrochemical method is rapid and easy to use, feasible and accessible to be used as an alternative to 2,2'-diphenyl-1-picrylhidrazyl spectrophotometric based method. (C) 2014 Elsevier Ltd. All rights reserved.

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Quantitative evaluation of organic acids in plants and foodstuff is important for flavour and nutritional studies and also could be used as indicator of bacterial activity. Organic acids occurring in foods are additives or end-products of carbohydrate metabolism of lactic acid bacteria (LAB). A good selection of LAB (and a criterion should be the content in organic acids) allows the control of mould growth and improves the shelf life of many fermented products and, therefore, reduces health risks due to exposure to mycotoxins. A simple, rapid (15 min) and reliable capillary electrophoresis method was partially validated for the simultaneous quantification of nine aliphatic (formic, oxalic, succinic, malic, tartaric, acetic, citric, lactic, butyric) and three aromatic (benzoic, phenyllactic and hydroxyphenyllactic) organic acids in the fermentation products of lactic acid bacteria. The method was validated in terms of linearity of response, limit of detection (LoD), limit of quantification (LoQ), precisions (i.e. intra-day, inter-day reproducibility) and recovery. The method is simple, rapid, reliable and cost-effective.

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In this paper, a liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry in negative mode method was developed for the identification and quantitative determination of 13 individual phenolics (chlorogenic acid, caffeic acid, coumaric acid, ferulic acid, (1)-catechin, (-)-epicatechin, rutin, quercitrin, isoquercitrin, fisetin, isorhamnetin, hesperidin and chrysin) from ethanolic extracts [30, 50 and 70% (w/v)] of Calendula officinalis, Hypericum perforatum, Galium verum and Origanum vulgare and some commercial extracts of these medicinal herbs. Correlation coefficients (r(2)) from calibration curves for all the compounds were between 0.9971 and 0.9996. Limit of detection was in the range of 0.070-0.280 mg/mL and limit of quantification was from 0.233 to 0.932 mg/mL. The method was partially validated and the results obtained are: the intra-and interday relative standard deviation values were within 0.086 and 2.821% and recovery values vary from 95.84% (coumaric acid) to 103.20% (rutin).

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Some plants collected (Mentha aquatica, Bidens tripartita and Ambrosia artemisiifolia) from an unusual habitat developed in recent years in Bucharest (the so-called Bucharest Delta) and the contents of polyphenolic compounds, short-chain organic acids and heavy metals, and radical scavenger activity, were determined. 12 polyphenolic compounds and 7 short-chain organic acids were quantified using high-performance liquid chromatography and capillary electrophoresis; Mentha aq. extracts presented the highest levels of rosmarinic acid (1.58 mg g(-1)) and ferulic acid (2.84 mg g(-1)) and Bidens extracts presented the highest concentrations of chlorogenic acid (0.44 mg g(-1)); the same extracts contain the most important levels of luteolin (0.52 mg g(-1)) or other flavonoids. All the heavy metals detected in the plants studied were found in very low levels (the highest was Pb(II) in Mentha aquatica, (12.84 +/- 0.48) mu g kg(-1)). The study sought to identify the active compounds and some contaminants in plants collected from the Bucharest Delta with the intention of eventual exploitation of the habitat and to enhance the knowledge of such human-modified ecosystems. (C) 2015 Institute of Chemistry, Slovak Academy of Sciences

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In this work, a simple, reliable and fast capillary electrophoresis method was developed and partially validated for simultaneous detection of 20 polyphenolic compounds (presumed to be found in propolis and plant extracts) in less than 27 min. The best results were obtained using 45 mM tetraborate buffer with 0.9 mM sodium dodecyl sulfate (pH = 9.35) as a background electrolyte. The polyphenolic compound order of elution was the following: resveratrol, pinostrobin, acacetin, chrysin, rutin, naringenin, isoquercitrin, umbelliferone, cinnamic acid, chlorogenic acid, galangin, sinapic acid, syringic acid, ferulic acid, kaempferol, luteolin, coumaric acid, quercetin, rosmarinic acid and caffeic acid. Linearity ranges used for compound quantification were satisfactory, presenting correlation coefficients between 0.997 and 0.999 for all 20 compounds. The method showed good performance characteristics: detection and quantification limits of 0.02 to 1.75 and 0.07 to 5.77 mu g mL(-1), respectively. The relative standard deviation values for repeatability did not exceed 4.86 % for intra-day assays and 5.07 % for inter-day assays. The recovery assays presented results between 87.4 and 114. 2 % for Origanum sample and between 85.0 and 111.0 % for propolis sample. The results obtained from the analysis of samples are in good correlation with literature data and bring new information about less studied samples such us aqueous Romanian propolis extracts and ethanolic Mentha aquatica extract.

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Dipyridine derivatives are used on large scale and pose significant environmental problems. We have synthesized dipyridine derivatives with: 5-chlorovaleric acid, alpha-dichlorhidrin, iodoacetamide and 11-bromoundecanoic acid. The synthesized substituted compounds were investigated by LC-MS. The adsorptive removal of dipyridine derivatives from aqueous solution has been studied using medicinal activated carbon. The adsorption rate has been investigated under the controlled process parameters including adsorption time, carbon and organic compound concentration. The results from this study demonstrated that the activated carbon can be used as a low-cost adsorbent for the removal of environmental cationic dipyridine derivatives from the water environment.

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The main goal of our study was to evaluate the effect of the individual administration of five lyophilized lactic acid bacteria strains (Lactobacillus fermentum 428ST, Lactobacillus rhamnosus E4.2, Lactobacillus plantarum FCA3, Lactobacillus sp. 34.1, Weissella paramesenteroides FT1a) against the in vitro simulated microbiota of the human colon using the GIS1 system. The influence on the metabolic activity was also assessed by quantitative determination of proteins and polysaccharides at each segment of human colon. The obtained results indicated that the lactic acid bacteria L. rhamnosus E4.2 and W. paramesenteroides FTa1 had better efficiency in synthesising exopolysaccharides and also a better probiotic potential and therefore could be recommended for use in probiotics products or food industry.

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An optimized electrochemical sensor was developed to assess the antioxidant capacity of carotenoids, accumulating during the life cycle of Haematococcus pluvialis cell cultures. The sensor was improved with a composite renewable surface made of immobilised phosphatidylcholine (PC) on magnetic nanobeads of iron oxide (Fe3O4) and PC/Fe3O4, and it was used to monitor the antioxidant properties of the ketocarotenoid astaxanthin against in situ generated phosphatidylcholine lipoperoxides. The surface configuration was able to mimic the natural position and orientation of astaxanthin in the cellular membrane, conferring to the whole experimental set-up good sensitivity for reactive oxygen species (limit of detection for peroxyl radicals 9.1 x 10(-10) mol L-1) with a linear response ranging between 10(-8) and 1.6 x 10(-6) mol L-1. The sensor has been proved suitable for both batch and flow measurements. The accuracy of the flow measurements was unaffected by the magnetic field intensity. Electrochemical measurements confirmed that natural astaxanthin is a more effective antioxidant than synthetic astaxanthin, vitamin E and lutein and the protective effect of astaxanthin correlates with its concentration inside the cell. The newly developed sensor is hence useable for in-line monitoring of whole-cell based industrial bioprocesses for the production of astaxanthin.

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The goal of this paper aimed the development of an inexpensive, reliable and easy-to-use biodevice for detection and monitoring of phenol and phenolic endocrine disruptors in water samples. X-Ray (XRD) diffraction technique was employed for physical characterization of the modified electrode surface, results revealing nanostructured layers assemblies of polycrystalline gold with (200) growth preferred orientation and gold crystallite size of 33.19 nm. Investigation of the modified surface charge transfer properties was performed using cyclic voltammetry technique highlighting a significant enhancement of the electron transfer rate. Dual signal amplification offered by synergistic effect of gold nanoparticle and reduced graphene oxide layers and tyrosinase led to competitive detection limits (7.2 x 10(-8) mol L-1 for phenol and 4.8 x 10(-7) mol L-1 for octylphenol) and sensitivities (416 nA/mu mol for phenol and 155 nA/mu mol for octylphenol). The obtained values of the K-m(app) and I-max/K-m(app) ratio confirmed a strongly dependence of the immobilized tyrosinase catalytic efficiency on the steric and electronic properties of the bulky side chain in the para position of the phenolic compound. The biodevice showed a percent recovery between 87 +/- 8% and 94 +/- 11% demonstrating a suitable degree of accuracy and confirming the application potential to the detection and monitoring of phenol and several endocrine disruptors in water samples. (C) 2015 Elsevier B.V. All rights reserved.

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Forty-four propolis samples collected from various regions of Romania were assessed by a validated method of high performance liquid chromatography with diode array detection for quantifying twelve important flavonoids and polyphenolic acids. The chromatographic data coupled with statistical analysis revealed two distinct groups of samples: the group corresponding to a plain climate and the group corresponding to plateau and upper hills climate. In addition to other statistical studies based on qualitative data, we can mention the compounds which are responsible for discrimination between propolis groups.

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The Romanian propolis was extracted in five different media, respectively, in water (pH 6.8), glycine buffer (pH 2.5), acetate buffer (pH 5), phosphate buffer (pH 7.4) and carbonate buffer (pH 9.2). The extracts presented different amounts of flavonoids and phenolic acids, increasing pH leading to higher concentrations of active compounds. Five variants of gold nanoparticles suspensions based on different pH Romanian propolis aqueous extracts were successfully synthesized. The obtained nanoparticles presented dimensions between 20 and 60 nm in dispersion form and around 18 nm in dried form, and different morphologies (spherical, hexagonal, triangular). Fourier transform infrared spectroscopy proved the attachment of organic compounds from propolis extracts to the colloidal gold suspensions and X-ray diffraction certified that the suspensions contain metallic gold. The obtained propolis gold nanoparticles do not exhibit any antibacterial or antifungal activity, but presented different catalytic activities and toxicity on tumour cells.

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We report the experimental results that refer to a Fourier transform Raman (FT-Raman) survey of thermally altered Baltic and Romanian amber and the related statistical interpretation of data using principal component analysis (PCA). Although FT-Raman spectra show several small changes in the characteristic features of the investigated amber samples which may be used for discrimination, their visual recognition is relatively difficult, especially when interpreting data from archeological samples, and thus multivariate data analysis may be the solution to more accurately assign the geological origin based on overall characteristic spectral features. The two categories of amber have different behavior in terms of degradation during the experimental alteration, and Romanian amber is more susceptible to physico-chemical transformations by the aggressive environment when compared with Baltic amber. The obtained data were in accordance with the Fourier transform infrared (FT-IR) remarks published previously in a dedicated journal. The Raman technique is an alternative method that requires little to no sample preparation, water does not cause interference, and the spectra can be collected from a small volume (1-50 mu m in diameter).

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Some plants collected (Mentha aquatica, Bidens tripartita and Ambrosia artemisiifolia) from an unusual habitat developed in recent years in Bucharest (the so-called "Bucharest Delta") and the contents of polyphenolic compounds, short-chain organic acids and heavy metals, and radical scavenger activity, were determined. 12 polyphenolic compounds and 7 short-chain organic acids were quantified using high-performance liquid chromatography and capillary electrophoresis; Mentha aq. extracts presented the highest levels of rosmarinic acid (1.58 mg g-1) and ferulic acid (2.84 mg g-1) and Bidens extracts presented the highest concentrations of chlorogenic acid (0.44 mg g-1); the same extracts contain the most important levels of luteolin (0.52 mg g-1) or other flavonoids. All the heavy metals detected in the plants studied were found in very low levels (the highest was Pb(II) in Mentha aquatica, (12.84 ± 0.48) μg kg-1). The study sought to identify the active compounds and some contaminants in plants collected from the "Bucharest Delta" with the intention of eventual exploitation of the habitat and to enhance the knowledge of such human-modified ecosystems. © 2015 Institute of Chemistry, Slovak Academy of Sciences.

Abstract

β-Carbolines are inhibitors of monoamine oxidases (MAO-A and MAO-B) and can be found in foods, hallucinogenic plant or various drugs. We have developed a fast analysis method for β-carbolines based on the inhibition of MAO. The enzymes were immobilized on screen-printed electrodes modified with a stabilized film of Prussian blue that contain also copper. We have used benzylamine as substrate for the enzymatic reaction and the hydrogen peroxide was measured amperometrically at -50 mV. The detection limits obtained were 5.0 μM for harmane and 2.5 μM for both harmaline and norharmane. The MAO-A is inhibited by all three tested β-carbolines (harmane, norharmane, and harmaline) while MAO-B is inhibited only by norharmane. The presence of norharmane in mixtures of β-carbolines can be identified based on the difference between the cumulative inhibition of MAO-A by all β-carbolines and MAO-B inhibition. The developed biosensors were used for food analysis. © 2015 Elsevier B.V. All rights reserved.

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capillary electrophoresis has proved to be a good alternative technique to high performance liquid chromatography for the investigation of various compounds due to its good resolution, versatility, simplicity, short analysis time and low consumption of chemicals and samples. This chapter presents a synthesis of our work regarding applications of capillary electrophoretic methods (capillary zone electrophoresis with diode array detection): the separation of small-chain organic acids from plants extracts, wines, lactic bacteria fermentation products, and the separation of polyphenolic compounds from propolis extracts, plant extracts and wines. Quantitative evaluation of organic acids in plants and foodstuff is important for flavour and nutritional studies, and also could be used as marker of bacterial activity. Organic acids occurring in foods are additives or end-products of carbohydrate metabolism of lactic acid bacteria. A good selection of lactic acid bacteria, in terms of content in organic acids, allows the control of mould growth and improves the shelf life of many fermented products and, therefore, reduces health risks due to exposure to mycotoxins. On the other side, the largely studied group of phytochemicals is polyphenols, an assembly of secondary metabolites with various chemical structures and functions and biological activities, which are produced during the physiological plant growth process as a response to different forms of environmental conditions. The methods for separation and quantification of organic acids and polyphenolic compounds were validated in terms of linearity of response, limit of detection, limit of quantification, precisions (i.e., intra-day, inter-day reproducibility) and recovery. The methods are simply, rapid, reliable and cost effective. © 2015 by Nova Science Publishers, Inc. All rights reserved.

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Dipyridine derivatives are used on large scale and pose significant environmental problems. We have synthesized dipyridine derivatives with: 5-chlorovaleric acid, alpha-dichlorhidrin, iodoacetamide and 11-bromoundecanoic acid. The synthesized substituted compounds were investigated by LC-MS. The adsorptive removal of dipyridine derivatives from aqueous solution has been studied using medicinal activated carbon. The adsorption rate has been investigated under the controlled process parameters including adsorption time, carbon and organic compound concentration. The results from this study demonstrated that the activated carbon can be used as a low-cost adsorbent for the removal of environmental cationic dipyridine derivatives from the water environment.

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A rapid, simple and stable biosensor for aspartame detection was developed. Alcohol oxidase (AOX), carboxyl esterase (CaE) and bovine serum albumin (BSA) were immobilised with glutaraldehyde (GA) onto screen-printed electrodes modified with cobalt-phthalocyanine (CoPC). The biosensor response was fast. The sample throughput using a flow injection analysis (FIA) system was 40 h(-1) with an RSD of 2.7%. The detection limits for both batch and FIA measurements were 0.1 mu M for methanol and 0.2 mu M for aspartame, respectively. The enzymatic biosensor was successfully applied for aspartame determination in different sample matrices/commercial products (liquid and solid samples) without any pre-treatment step prior to measurement.

Abstract

The anticholinesterase activity of four biochemical pesticides: spinosad, pyrethrum, neem bark extract and veratrine was tested against one acetylcholinesterase extracted from Electrophorus electricus and two from Drosophila melanogaster. Pyrethrum, neem bark extract, and veratrine induced a dose-related inhibition of a variable type. Electric eel cholinesterase was inhibited uncompetitively by neem bark extract, the inhibition of the wilde-type fruit fly enzyme by pyrethrum was competitive, and the other enzyme-biochemical pesticide inhibitions were non-competitive. The sensitivity of each enzyme toward biochemical pesticides was variable. (C) Pesticide Science Society of Japan

Abstract

The aim of this study was to determine the best conditions to obtain the highest total polyphenol content from Salvia officinalis hydroalcoholic and aqueous extracts and to study the main bioactive compounds and the antioxidant activity of the concentrate obtained during ultrafiltration. 8%, 10% and 15 % (mass concentration) hydroalcoholic extracts of Salvia officinalis in 70% ethanol and an aqueous extract (8%) were prepared. The obtained extracts were further purified and concentrated through membrane procedures (ultrafiltration). The aqueous extracts were successively concentrated through ultrafiltration membranes of regenerated cellulose with 10000 Da, than 5000 Da and 3000 Da, the highest concentration being obtained using the 3000 Da Millipore membranes. For hydroalcoholic extracts 3 types of membranes were used: Millipore ultrafiltration membranes with cut-off of 10.000 Da and 5.000 Da and polysulfone composite membrane (PSF). The contents of total polyphenols, proteins, reducing sugars and flavones were determined. The values ranged between: 321.23 - 404.21 mu g/mL - polyphenols, 1.04 - 1.72 mg/mL - proteins, 26.01 - 99.48 mg/mL - flavones and 35.05 - 138.16 mu g/mL - sugars. The concentrated extracts showed promising levels of DPPH radical scavenging activity (42.12%-70.82%), the highest values being obtained for the extracts concentrated by Millipore membranes 5000 Da.

Abstract

We have modified a glassy carbon electrode (GCE) with nanoparticles composed of a 4,4'-bipyridinesilver coordination polymer (CP) and showed that this CP can be applied to the sensitive differential pulse voltammetric analysis of the ions Hg(II), Cu(II) and Pb(II). The coordination polymer was prepared by mixing a solution of silver nitrate and 4,4'-bipyridine at room temperature. The surface of the GCE was modified with an organic layer of synthesized 1-[(4-nitrophenyl)methyl]-4,4'-bipyridinium and silver ions, which caused the binding of the added Ag-bipy CP. Anodic (oxidative) peaks of the electrode were at +300 mV for Hg(II), -70 mV for Cu(II), and at -540 mV for Pb(II) [versus Ag/AgCl]. Under optimal conditions, calibration graphs were linear in concentration ranges from 0.2 to 10 mu g L-1 for Hg(II), from 1.3 to 6.4 mu g L-1 for Cu(II), and from 4.1 to 20.7 mu g L-1 for Pb(II). The respective detection limits were 0.09 mu g L-1 Hg(II), 0.71 mu g L-1 Cu(II) and 2.3 mu g L-1 Pb(II). Relative standard deviation was 3.2% at a level of 4 mu g L of Hg(II) for n = 10. The modified electrode was applied to the analysis of Hg(II) in spiked fish samples, and of Cu(II), Pb(II), and Hg(II) in spiked plant samples, and recoveries ranged from 90 to 108%. This is the first paper that presents the use of 4,4'-bipyridine-silver coordination polymer for heavy metal electrochemical detection.

Abstract

This study was meant to determine the inhibitory activity of tannins and flavonoid compounds from Geranium robertianum, Helleborus purpurascens and Hyssopus officinale plant polyphenol rich extracts against urease and alpha-chymotrypsin. The G. robertianum, H. purpurascens and H. officinale extracts were purified and concentrated by microfiltration and ultrafiltration. Phenolic compounds including flavonoids and tannins have been linked to many pharmacological activities. Thus, the polyphenolic content of the extracts was assessed by UV-Vis spectroscopy and HPLC. The concentrated extracts enriched in polyphenolic compounds (flavonoids, tannins and phenolic acids) showed a significant inhibition against urease from jack bean (over 90%), whereas in case of the alpha-chymotrypsin, they proved to have an inhibition below 54%. The results of this support the use of G. robertianum, H. purpurascens and H. officinale polyphenolic extracts as potential sources of urease inhibitors. Among the three plant extracts tested, H. officinale polyphenolic extracts exhibited a high inhibitory activity (92.67%) against urease and low inhibition (19.6%) against alpha-chymotrypsin and could be considered as possible remedy in ulcer treatment.

Abstract

Experimentally developed ceramic pots, with two different sizes of grain, were half-filled with wine and subjected to thermal alteration at constant elevated temperature ((60 +/- 2)A degrees C) in darkness for 12 weeks. This work sought to characterise the samples thereby obtained from chemical and mineralogical perspectives using scanning electron microscopy and an energy-dispersive X-ray microanalysis system (SEM-EDX), Fourier transform infrared spectroscopy (FTIR) and capillary electrophoresis (CE) with UV detection as an alternative to chromatographic methods, due to its good resolution, automation, simplicity, high speed, low consumption of chemicals and short time required for sample preparation. The capillary electrophoresis method was used for the detection of five wine biomarkers: succinic acid, malic acid, tartaric acid, citric acid and lactic acid. In general, it was noted that the fine-grained ceramic assortment retained the organic material better than the coarser-grained ceramics. An interesting observation derived from this study was that not only could tartaric acid be considered as a biomarker for wine residues in archaeological pottery, but malic acid could also act similarly for white wine and lactic acid for red wine.

Abstract

Indium doped tin oxide (ITO) electrodes were functionalized with gold nanoparticles (GNPs) and cysteamine monolayer to enhance the heterogeneous electron transfer process of laccase from Trametes versicolor. The assembly of GNP on ITO support was performed through generation of H+ species at the electrode surface by hydroquinone electrooxidation at 0.9 V vs Ag/AgCl. Uniform distribution of gold nanoparticle aggregates on electrode surfaces was confirmed by atomic force microscopy. The size of GNP aggregates was in the range of 200-500 nm. The enhanced charge transfer at the GNP functionalized ITO electrodes was observed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy. Electrocatalytic behavior of laccase immobilized on ITO modified electrode toward oxygen reduction reaction was evaluated using CV in the presence of 2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfuric acid (ABTS). The obtained sigmoidal-shaped voltammograms for ABTS reduction in oxygen saturated buffer solution are characteristic for a catalytic process. The intensity of catalytic current increased linearly with mediator concentration up to 6.2 x 10(-4) M. The registered voltammogram in the absence of ABTS mediator clearly showed a significant faradaic current which is the evidence of the interfacial oxygen reduction. (C) 2014 Elsevier B.V. All rights reserved.

Abstract

The aim of the present work was to widen the application of an in-house developed fast, flexible and sensitive high performance liquid chromatography (HPLC) method to the assessment of cefotaxime sodium from aqueous samples. The method was applied to establish the release profile of cefotaxime sodium immobilised in MCM-41 nanoparticles using pH-controlled release in an aqueous medium. The analytical method proved to be sensitive, repeatable (RSD < 1.5 %) and reproducible (RSD < 1 %) in the studied concentration range (0.01-10 mu g.mL(-1)). The limit of detection and limit of quantification were 0.036 and 0.12 mu g.mL(-1), respectively, suitable for the analysis of the release of a single active ingredient, and the analysis time was short (10 min).

Abstract

A method based on reversed-phase liquid chromatography (RP-LC) with diode array detection (DAD) has been developed and validated in order to quantitate several polyphenols from different extracts. Samples were separated on a Fortis C18 reversed-phase column (250 x 4.6 mm, 5 mu m) with a gradient of acetonitrile and aqueous phosphoric acid, pH=2.5. The complete separation of seventeen polyphenols was achieved within 60 min. All calibration curves expressed good linearity (r(2) > 0.997) within the test range. The recovery of this method was in the range 88.12-107.87% and for the intra-day and inter-day assays, the values of deviation coefficient were less than 5%. The assay was successfully applied to the quantitation of polyphenols from 9 samples of propolis ethanolic extracts purchased from Roumanian market. The results indicated that this developed RP-LC assay could be readily utilized as a quality control method of various natural extracts.

Abstract

1-[(4-nitrophenyl) methyl]-4,4'-bipyridinium (N-PMB) was synthesized by refluxing 4,4'-bipyridine and 4-nitrobenzylchloride. A stable film of 1-phenylmethyl-4,4'-bipyridine (PMB) was successfully electrografted on glassy carbon electrodes by the reduction of the diazonium moieties generated in situ. High antifouling ability was obtained for the PMB modified electrode which makes it a useful sensor device for environmental waters monitoring. The modified electrode was used as an amperometric sensor for mediated hydrogen peroxide detection at -0.5 V. The calibration curve was linear from 5 to 60 mu M H2O2 (R-2=0.9978, n=7) with a detection limit of 0.25 mu M. PMB modified electrodes was able to detect oxygen in river water with good sensitivity, selectivity and reproducibility.

Abstract

Increased need for non-destructive investigation methods in archaeology has become a major issue since sampling is in most cases restricted in view of the importance or uniqueness of the objects. For this reason, preliminary investigation using non-destructive techniques was performed on five samples of amber beads obtained from different excavation and archaeological sites. The use of FTIR and micro-Raman analysis revealed the presence of carboxyl, peroxide, hydroxyl, and complex ester functional groups as well as single and double bonds in the structure of the studied resin varieties. Further analysis of the amber samples from both archaeological and geological types by XPS, XRF, and SEM showed the presence of sulfur and a wide range of trace elements on the surface of the analysed samples. Our results proved that the combination of structural-molecular and surface elemental techniques for amber characterisation provides a very useful and simple methodology for the description of geological and archaeological amber samples from different regions of Europe. (C) 2013 Institute of Chemistry, Slovak Academy of Sciences

Abstract

This study was meant to determine the inhibitory activity of tannins and flavonoid compounds from Geranium robertianum, Helleborus purpurascens and Hyssopus officinale plant polyphenol rich extracts against urease and α-chymotrypsin. The G. robertianum, H. purpurascens and H. officinale extracts were purified and concentrated by microfiltration and ultrafiltration. Phenolic compounds including flavonoids and tannins have been linked to many pharmacological activities. Thus, the polyphenolic content of the extracts was assessed by UV-Vis spectroscopy and HPLC. The concentrated extracts enriched in polyphenolic compounds (flavonoids, tannins and phenolic acids) showed a significant inhibition against urease from jack bean (over 90%), whereas in case of the α-chymotrypsin, they proved to have an inhibition below 54%. The results of this support the use of G. robertianum, H. purpurascens and H. officinale polyphenolic extracts as potential sources of urease inhibitors. Among the three plant extracts tested, H. officinale polyphenolic extracts exhibited a high inhibitory activity (92.67%) against urease and low inhibition (19.6%) against α-chymotrypsin and could be considered as possible remedy in ulcer treatment. © 2014 Informa UK Ltd.

Abstract

The aim of the present work was to develop a spectrofluorimetric method of analysis applicable to β-lactam antibiotic cefotaxime sodium from aqueous solutions. We found interest in developing a fluorimetric method, using a luminescence spectrometer. Cefotaxime sodium was analysed by derivatization with a specific fluorescent compound namely 4-fluoro-7-nitrobenzofurazan which is a fluorophore used in the detection of amines. The method developed proved to be suitable for this purpose. This method was applied in the controlled release, in phosphate buffer solutions (pH=7.4), of cefotaxime sodium from hybrids obtained by the immobilization of the antibiotic in MCM-41 nanoparticles. © 2009 Universitatea Politehnica Bucuresti.

Abstract

1-[(4-nitrophenyl)methyl]-4,4'-bipyridinium (N-PMB) was synthesized by refluxing 4,4'-bipyridine and 4-nitrobenzylchloride. A stable film of 1-phenylmethyl-4,4'-bipyridine (PMB) was successfully electrografted on glassy carbon electrodes by the reduction of the diazonium moieties generated in situ. High antifouling ability was obtained for the PMB modified electrode which makes it a useful sensor device for environmental waters monitoring. The modified electrode was used as an amperometric sensor for mediated hydrogen peroxide detection at -0.5 V. The calibration curve was linear from 5 to 60 μM H2O2 (R2=0.9978, n=7) with a detection limit of 0.25 μM. PMB modified electrodes was able to detect oxygen in river water with good sensitivity, selectivity and reproducibility. © 2014 The Authors. Published by ESG.

Abstract

A new type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane have been developed for the encapsulation and controlled release of gallic acid. The morphology of the composite membrane was investigated by infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM), whereas swelling gallic acid and release properties were investigated by UV-visible spectroscopy. The release behavior with pH changes was also explored. The composite membrane based on chitosan/2-hydroxypropyl-β-cyclodextrin with gallic acid included showed improved antioxidant capacities compared to plain chitosan membrane. The information obtained in this study will facilitate the design and preparation of composite membrane based on chitosan and could open a wide range of applications, particularly its use as an antioxidant in food, food packaging, biomedical (biodegradable soft porous scaffolds for enhance the surrounding tissue regeneration), pharmaceutical and cosmetics industries.

Abstract

1-[(4-nitrophenyl) methyl]-4,4'-bipyridinium (N-PMB) was synthesized by refluxing 4,4'-bipyridine and 4-nitrobenzylchloride. A stable film of 1-phenylmethyl-4,4'-bipyridine (PMB) was successfully electrografted on glassy carbon electrodes by the reduction of the diazonium moieties generated in situ. High antifouling ability was obtained for the PMB modified electrode which makes it a useful sensor device for environmental waters monitoring. The modified electrode was used as an amperometric sensor for mediated hydrogen peroxide detection at -0.5 V. The calibration curve was linear from 5 to 60 mu M H2O2 (R-2=0.9978, n=7) with a detection limit of 0.25 mu M. PMB modified electrodes was able to detect oxygen in river water with good sensitivity, selectivity and reproducibility.

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Numerous amperometric biosensors have been developed for the fast analysis of neurotoxic insecticides based on inhibition of cholinesterase (AChE). The analytical signal is quantified by the oxidation of the thiocholine that is produced enzymatically by the hydrolysis of the acetylthiocholine pseudosubstrate. The pseudosubstrate is a cation and it is associated with chloride or iodide as corresponding anion to form a salt. The iodide salt is cheaper, but it is electrochemically active and consequently more difficult to use in electrochemical analytical devices. We investigate the possibility of using acetylthiocholine iodide as pseudosubstrate for amperometric detection. Our investigation demonstrates that operational conditions for any amperometric biosensor that use acetylthiocholine iodide must be thoroughly optimized to avoid false analytical signals or a reduced sensitivity. The working overpotential determined for different screen-printed electrodes was: carbon-nanotubes (360 mV), platinum (560 mV), gold (370 mV, based on a catalytic effect of iodide) or cobalt phthalocyanine (110 mV, but with a significant reduced sensitivity in the presence of iodide anions).

Abstract

The present work describes the development of a nanocomposite system and its application in construction of a new amperometric biosensor applied in the determination of total polyphenolic content from propolis extracts. The nanocomposite system was based on covalent immobilization of laccase on functionalized indium tin oxide nanoparticles and it was morphologically and structural characterized. The casting of the developed nanocomposite system on the surface of a screen-printed electrode was used for biosensor fabrication. The analytical performance characteristics of the settled biosensor were determined for rosmarinic acid, caffeic acid and catechol (as laccase specific substrate). The linearity was obtained in the range of 1.06x10(-6) - 1.50x10(-5) mol L-1 for rosmarinic acid, 1.90x10(-7) - 2.80x10(-6) mol L-1 for caffeic acid and 1.66x10(-6) - 7.00x10(-6) mol L-1 for catechol. A good sensitivity of amperometric biosensor 141.15 nA A mu mol(-1) L-1 and fair detection limit 7.08x10(-8) mol L-1 were obtained for caffeic acid. The results obtained for polyphenolic content of propolis extracts were compared with the chromatographic data obtained by liquid-chromatography with diode array detection.

Abstract

Detection of low concentrations of heavy metals in environmental samples is of particular interest because most of them represent persistent, highly toxic pollutants. Cu2+ detection in environmental samples is important because it is typical heavy metal, being an essential element for human beings but at higher concentrations it can create health risks. Due to the accumulation steps involved, anodic stripping voltammetry (ASV) is one of the most sensitive techniques used for the detection of low concentrations of metal ions form different environmental samples. In order to minimize sample loss during sample collection, storage and transportation it is of particular interest to perform in situ rapid and reliable routine analysis. In the present paper we describe the use of a simple, disposable pencil graphite electrode (PGE) for the determination of Cu from river water samples by mercury film anodic stripping voltammetry. The investigated water samples were collected during a period of 3 years (2009-2011), from six sampling points situated along the lower part of the Prut River (Romania). ASV measurements were performed in the presence of Hg2+ in 0.1 M HNO3 at a carbon pencil graphite working electrode. Standard addition method was applied for the quantification of Cu2+. The Cu2+ content of the most river water samples analysed exceeded 2 mu g/ L (MEWM, 2006), the maximum admitted concentration for surface waters, and these could be due to the anthropogenic activities in the region (e. g. the largest steel factory in Romania is located in the vicinity of the sampling area). Samples show an additional importance as the region is included in a protected area, Lower Prut Floodplain Natural Park, and trace elements transfer along the aquatic food chain has been previously documented (Matache et. al, 2012). The results obtained by ASV on PGE agreed well with those obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES) using the Romanian standard SR ISO 11885-09. The sensor used in this work has shown some important advantages such being cheap, sensitive and able to generate reproducible results using a simple and direct electrochemical protocol. By using this type of disposable working electrodes and a portable electrochemical analysis system the developed method can be applied to the determination of copper ions directly at the sampling point.

Abstract

They were characterized by Fourier transform infrared spectroscopy (FTIR). The efficiency of EA entrapment revealed values >= 50%. The released ellagic acid quantities were spectrophotometrically determined at various time intervals: 1, 2, 3, 7 days, and various pH: 3.0, 7.5, 8.0, 9.0. The best cumulative release of ellagic acid from membranes was obtained at lowest pH, pH=3. The antioxidant capacity of EA released from membranes was evaluated by inhibition percent of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The best result was found also at pH=3.0, 20% DPPH inhibition (at 48h). The properties of such membranes recommend them as biomaterial with controlled antioxidant biological activity.

Abstract

This paper presents the effect of acrolein on three dehydrogenases and proposes a fast spectrometric method for acrolein analysis. We have found that alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (AlDH) are inhibited by low acrolein concentrations (0.2?mM) while inhibition of glutamate dehydrogenase (GDH) is not observed even at higher acrolein concentrations (1?mM). Acrolein is a suicide substrate for AlDH and ADH inhibition by acrolein is competitive. Cysteine (L-Cys) and glutathione (GSH) react with acrolein and thus reduce its expected inhibitory effect. ADH was chosen to develop a spectrophotometric method for acrolein analysis based on enzyme inhibition. The calibration curve is linear between 0.2 and 1.0?mM acrolein.

Abstract

The main products generated by lipid peroxidation are the lipid hydroperoxides, compounds that are involved in the pathology of several diseases and in the process of food rancidification. In this context, simple, fast, and reliable analytical tools for the determination of lipid hydroperoxides are highly required. The present work describes the development of a single use ferrocenemethanol modified carbon screen-printed electrode for the determination of lipid hydroperoxides. The modified electrode is equally applicable to evaluation of peroxidation inhibition degree of two well-known antioxidants. The performance characteristics of the proposed non-enzymatic sensor are: linear working range 6.0 x 10(-6) to 2.7 x 10(-4) mol L-1, limit of detection 1.7 x 10(-6) mol L-1, upper control limit 3 x 10(-4) mol L-1 and sensitivity 826.53 nA mM(-1); the required time to reach the steady state was 60 s. The sensor was then applied for the determination of lipid hydroperoxide formation from four real samples of vegetal oils, walnut, sunflower, linseed and soybean oils, the results being expressed as linoleic acid equivalents. Furthermore, the efficacy of Trolox and butylated hydroxyanisole in inhibiting lipid hydroperoxide formation was tested.

Abstract

A disposable amperometric biosensor was developed for the detection of total polyphenolic compounds from tea infusions. The biosensor was designed by modifying the surface of a carbon screen-printed electrode with platinum nanoparticles and reduced graphene oxide, followed by the laccase drop-casting and stabilization in neutralised 1% Nafion solution. The obtained biosensor was investigated by scanning electron microscopy and electrochemical techniques. It was observed that platinum nanoparticles-reduced graphene oxide composite had synergistic effects on the electron transfer and increased the electroactive surface area of the carbon screen-printed electrode. The constructed analytical tool showed a good linearity in the range 0.2-2 mu M for caffeic acid and a limit of detection of 0.091 mu M. The value of Michaelis-Menten apparent constant was calculated from the electrochemical version of Lineweaver-Burk equation to be 2.75 mu M. This disposable laccase biosensor could be a valuable tool for the estimation of total polyphenolic content from tea infusions. (C) 2013 Elsevier B.V. All rights reserved.

Abstract

Pristine graphene platelets and graphene oxide were used as electrode modifiers, aiming the investigation of their electrochemical efficacy towards beta-nicotinamide adenine dinucleotide (NADH). The electrochemical detection of NADH is one of the most studied areas of bioelectroanalysis because of the ubiquity of NAD(P)H-based enzymatic reactions in nature. Commercially available graphene and laboratory prepared graphene oxide were used to modify glassy carbon electrodes and the behaviour of such modified electrodes against potassium ferricyanide (III) and NADH was reported. Relying on the graphene-modified transducer, l-lactic dehydrogenase (l-LDH) was successfully immobilised in a 1 % Nafion(A (R)) membrane. The developed biosensor, working at +250 mV versus Ag/AgCl reference electrode, was used to assess l-lactic acid in four different types of yogurts, revealing an l-lactic acid concentration ranging between 0.3 and 0.6 %.

Abstract

A fluorimetric method for the determination of cysteine (CSH) and cystine (CSSC) at nanomolar concentrations is reported. The detection limit was 2.46x10(-11) M for CSH when derivatisation is performed by 5-iodoacetamidofluorescein (5-IAF) and respectively 7.2x10(-10) M when monobromobimane was used as fluorescent reagent. The dynamic range of analytical response was 3x10(-10) - 3x10(-8) M ( in the case of CSH-5-IAF). The method was further applied to determine the [CSH]/[CSSC] ratio at nanomolar concentration levels as potential marker of aminoacids oxidative status. An original algorithm to calculate the exact concentrations for each form was established, being provided even the experimental data to support it. Zinc influence on avoiding CSH oxidation was studied. Data were confirmed by high-performance liquid chromatography with fluorescence detection.

Abstract

Introduction A recently developed laccase based biosensor is used for polyphenols determination from in vitro Salvia cultures, the results being expressed as rosmarinic acid equivalent content. Objective The aim of this work was to use a previously developed laccase biosensor for the determination of total phenolic content from in vitro cultivated Salvia, and to support the biosensors further application for the assessment of polyphenols metabolites. Methodology The biosensor was constructed by drop casting 3 mu L of laccase solution and stabilisation with 0.1 % Nafion solution onto a DropSens carbon screen-printed electrode. Electrochemical measurements were carried out in a 0.1 mol/L phosphate buffer (pH 4.50), the applied working potential being -30 mV versus reference electrode. Results The response of the biosensor developed was characterised in terms of repeatability, accuracy and precision; the limit of detection was 7.5?x?10-7 mol/L, the limit of determination was 9.5?x?10-7 mol/L, and linear response range for rosmarinic acid was 1 x 10-610-5 mol/L. Conclusion A stable, sensitive and simple biosensor based on laccasenafion was used for monitoring the total polyphenolic content from two in vitro cultivated plants. The biosensor response was free of electrochemical interferences and of possible interferences from growth media constituents, demonstrating a high sensitivity for rosmarinic acid determination in cell culture suspensions. Copyright (c) 2012 John Wiley & Sons, Ltd.

Abstract

The content in short-chain organic acids of medicinal herbs is important for their taste, flavour and therapeutic effects. Short-chain organic acids from three types of medicinal plants were analyzed, chamomile (Matricaria recutita, Asteraceae), linden (lime, Tilia platyphyllos, Tiliaceae) and mint (menthe, Mentha piperita, Lamiaceae) as infusion and decoction. A diode array-capillary electrophoresis method has been partially validated that permits the direct measurement of 5 short-chain organic acids, respectively succinic, malic, citric, tartaric and lactic acid, in medicinal plants extracts (teas). The method is simple, rapid, reliable and low consumption of resources in comparison with chromatographic methods; it could be applied on other natural products and extracts (coffee, honey, fruits, juices and wines) and could be developed on a, wide series of short-chain organic acids.

Abstract

A simple, fast and sensitive high-performance liquid chromatography/electrospray ionization-mass spectrometry method is described and validated in terms of linearity, accuracy/recovery and reproducibility, as well as limit of detection for the determination of ascorbic acid from grape (Vitis vinifera L.) samples from Murfatlar vineyard. Good linearity (correlation factor > 0.9970) was achieved in the concentration range 0.5-15 mu g mL(-1) for AA in acetic acid 0.1% solution. The obtained RSD values (below 5%) indicated excellent repeatability of the proposed method. The limit of detection was 0.32 mu g mL(-1) while the recovery ranged between 96.86 and 102.41%. The advantages of the method are: small amounts of sample and solvents, short analysis time and minimum steps for sample preparation.

Abstract

The aim of this study was to evaluate the antioxidant and antibacterial potential of essential oils (EOs) of two Moroccan aromatic herbs essential oils: Lippia citriodora and Cedrus atlantica. The composition of these species was analyzed by GC/MS and 54 compounds were identified. The essential oil extracted from L. citriodora contained, as main components citral (19.07%), cuparene (12.33%), 1-butenylidenecyclohexane (9.4%), eucalyptol (7.9%), spathulenol (7.55%), beta-cyclocitral (6.54%) and caryophhyllene oxide (6.27%) and the major constituents of the Cedrus atlantica oil were beta-himachalene (29.4%), alpha-longipinene (20.75%), beta-chamigrene (14.39%), longifolene (V4) (11.61%) and alpha-himachalene (5.1%). The oils were also subjected to screening for their possible antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the reducing power assays. The antibacterial activity of these essential oils has been evaluated against two bacteria (Staphylococcus aureus and Escherichia coli) with significant importance for food industry and we determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of each essential oil. The tested essential oils showed a variable degree of antimicrobial activity. These results suggest that the essential oil from Lippia citriodora has potential to be used as a natural antioxidant and antimicrobial agent in food processing.

Abstract

The natural methyl donor group, S-adenosylmethionine and its product, S-adenosylhomocysteine play an important role in many biochemical reactions involving transmethylation reactions. These compounds can be used as biomarkers in incipient diagnosis of various pathological disorders therefore the validation of a suitable method to routinely analysis of these compounds is very important. In this paper, a high performance liquid chromatrography method for S-adenosylmethionine and S-adenosylhomocysteine measurement as fluorescent 1,N (6)-ethanoderivatives from biological samples was validated in terms of selectivity, linearity range of the response (R > 0.9993), detection limit (9 x 10(-9) and 4.4 x 10(-9) molL(-1)), the limit of quantitation (9.7 x 10(-9) and 5.7 x 10(-9) mol L-1), precision, trueness and robustness. The method for quantification simultaneous of these compounds is rapid, sensitive and precise and appropriate for clinical analysis.

Abstract

They were characterized by Fourier transform infrared spectroscopy (FTIR). The efficiency of EA entrapment revealed values ≥ 50%. The released ellagic acid quantities were spectrophotometrically determined at various time intervals: 1, 2, 3, 7 days, and various pH: 3.0, 7.5, 8.0, 9.0. The best cumulative release of ellagic acid from membranes was obtained at lowest pH, pH=3. The antioxidant capacity of EA released from membranes was evaluated by inhibition percent of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The best result was found also at pH=3.0, 20% DPPH inhibition (at 48h). The properties of such membranes recommend them as biomaterial with controlled antioxidant biological activity.

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This study aimed to assess the antioxidant compound effects on oxidisable substrates, using an effective bio-mimetic system based on human low density lipoproteins (LDL). Thermally generated radicals induce LDL oxidative changes to be identified and quantified. The bio-mimetic system thus developed responded linearly to radicals' concentration over a range of 10(-6)-10(-5) mol L-1. Cu2+ accentuates lipoperoxidation but, when rosmarinic acid was present, Cu2+ produced an unexpected effect, i.e. increased antioxidant efficiency against lipoperoxidation. Rosmarinic acid inhibits production of lipoperoxides by up to 30 % in the absence of Cu2+ and up to 70 % in its presence when the rosmarinic acid-to-Cu molar ratio is 1: 1.

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This work focuses on using analytical methods, such as Fourier transform Infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC) with mass spectrometry (MS) detection to assess archaeological and geological amber. The main goal of this study is to apply the previously developed and optimized analytical methods in verifying criteria to ascribe and characterize the origin of materials found in archaeological sites. The proposed LC-MS method was successfully applied for the quantification of succinic acid content both in geological and archaeological samples of amber and offers excellent linearity between 0.1 and 5A mu g mL(-1). The developed FTIR method provided some criteria which is able to differentiate between Baltic and Romanian amber (Romanite) that furthermore validates on archaeological amber artefacts.

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A simple, fast and sensitive capillary electrophoresis method was developed and partially validated for the determination of several water-soluble vitamins from food samples. The separation of five vitamins from group B and ascorbic acid was carried out by using capillary electrophoresis with a fused-silica capillary and UV detection (214 nm). The optimum conditions were: 20mM NaH2PO4 and 15mM SDS background electrolyte, pH=9 and voltage 25kV. The method exhibited good results concerning precision (RSD % < 5), linear calibration curves (R-2>0.99) and selectivity in the concentration range studied. The advantages of the method are: small amounts of sample and reagents, short analysis time and minimum steps. The results were confirmed and are comparable to those obtained by high performance liquid chromatography coupled with mass spectrometry.

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Hyaluronic acid (HA) was separated by capillary electrophoresis (CE) under normal polarity in phosphate buffer pH 7.4. HA-derived monosaccharide obtained after hydrolysis with trifluoroacetic acid and derivatization with 4-aminobenzoic acid ethyl ester were separated by capillary electrophoresis under normal polarity in borate buffer pH 11. Both CE methods are simple and reliable for quantifying of HA in several natural extracts. The sensitivity of the methods (18.6 +/- 0.36 mu g/mL detection limit for intact HA and 1.09 +/- 0.07 mu g/mL for derivatized monosaccharide) is acceptable for an UV detection and to evaluate the content of HA in connective tissues extracts and, eventually, in cosmetic and pharmaceutical formulations.

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A fast and selective method based on high-performance liquid chromatography with diode array and atmospheric pressure chemical ionization-mass spectrometry detection (HPLC-DAD-APCI-MS) was developed and optimized to assess specific food samples content in carotenoids. Two compounds were chosen as significant carotenoids with respect to nutritional value, beta-carotene, and lycopene. The optimum conditions suitable for samples analysis were: a mobile phase of methanol: water (95: 5) (A) and acetonitrile: methylene chloride (90: 10) (B), with a gradient elution: 0-4 min 0% B, 4-7 min 20% B, 7-10 min 50% B, 0-10 min flow 0.1 mL/min, 10-30 min 90% B, 10-30 min flow 0.2 mL/min. Analytes were separated within 30 min on a C18 column and a diode array detection (450 nm for beta-carotene and 470 nm for lycopene). The linear dependence between peak area and concentration ranged from 5x10(-7) molL(-1) to 5x10(-5) molL(-1) (r=0.9998, n=9) for beta-carotene and respectively 7.5x10(-7) molL(-1) to 7.5x10(-5) molL(-1) (r=0.9986, n=5) for lycopene. The optimized method was used to quantify beta-carotene and lycopene in bakery products enriched with carotenoids devoted to the nutrition of aged population, method that could be standardized and used for bakery products quality control.

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In the present study Fourier transform infrared spectroscopy in the reflectance mode (FTIR-reflectance) - was performed on well preserved archaeological amber, originating from three Romanian archaeological sites of Roman and Byzantine cultures, which did not allow sampling material. Resulting spectra were subjected to multivariate data analysis (MDA) using Principal Components Analysis (PCA). In the light of the FTIR-reflectance bands of archaeological samples from the region 1275 to 1155 cm(-1) and 900-600 cm(-1) we could conclude that the samples from first two locations, Rosia Montana and Nufaru, are made from amber of Baltic origin. In the case of the third location, Isaccea, we take into account the possibility of a mixture of raw materials, both Baltic and Romanian amber. These assertions are supported by statistical analysis and the historical context. Besides the FTIR spectra comparison or other analytical data, it is very important to correlate any information about the material (colour, conservation status, historical context, connections with other artefacts) and the statistical analysis in order to favour safe conclusions. (C) 2012 Elsevier Ltd. All rights reserved.

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The paper reports the successful application of membranes processes to obtain good quality extracts with compounds of high antioxidative activity and therapeutic value. In this study, the phenolic compounds from two plant species used in Romanian ethno-medicine were investigated and their antioxidant/and cytotoxic activities evaluated. Three extracts prepared from Geranium robertianum and Symphytum officinale were concentrated by microfiltration and ultrafiltration. The levels of phenolic compounds and flavonoids were determined by UV-Vis spectroscopy and high-pressure liquid chromatography (HPLC). The free-radical scavenging activity of the concentrated extracts was determined by the 2,2-diphenyl-l-picrylhydrazyl radical (DPPH) method. The preliminary tests of cytotoxic activity for the concentrated extracts were performed on human epidermoid laryngeal carcinoma cell line (Hep-2p) and normal monkey kidney cells (RM). The results showed that all the concentrated extracts had a very low cytotoxicity against healthy cells, but a significant cytotoxic effect on Hep-2p tumor cells. The concentrated extracts had a high antioxidant activity (% DPPH inhibition > 80 %).

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The inhibition characteristics of three different protein phosphatases by three microcystin (MC) variants-LR, YR, and RR-were studied. The corresponding K (I) for each enzyme-MC couple was calculated. The toxicity of MC varies in the following order: MC-LR > MC-YR > MC-RR. The sensitivity of the enzymes increased in the following order: mutant PP2A < mutant PP1 < natural PP2A. The best limit of detection obtained was 21.2 pM MC-LR using the most sensible enzyme. Methanol, ethanol, and acetonitrile up to 2 % (v/v) may be used in inhibition measurements. An artificial neural network (ANN) was used to discriminate two MC variants-LR and YR-using the differences in inhibition percentages measured with mutant PP1 and natural PP2A. The ANN is able to analyze mixtures with concentrations ranging from 8 to 98 pM MC-LR and 31 to 373 pM MC-YR.

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Pollutants transfer via the food chain was investigated in a wetland ecosystem from the Lower Prut Floodplain Natural Park in Romania. Trace elements (Cd, Cu, Pb and Zn) were determined by Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES) from samples belonging to primary producers and primary and secondary consumers, and also from water and sediments samples. Non-essential trace elements as Cd and Pb exhibited low concentrations in molluscs and fish, but zinc had shown concentration up to 745.28 mu g/g in Cyprinus carpio.

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This work focuses on using analytical methods, such as Fourier transform Infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC) with mass spectrometry (MS) detection to assess archaeological and geological amber. The main goal of this study is to apply the previously developed and optimized analytical methods in verifying criteria to ascribe and characterize the origin of materials found in archaeological sites. The proposed LC-MS method was successfully applied for the quantification of succinic acid content both in geological and archaeological samples of amber and offers excellent linearity between 0.1 and 5μg mL -1 . The developed FTIR method provided some criteria which is able to differentiate between Baltic and Romanian amber (Romanite) that furthermore validates on archaeological amber artefacts. © Versita Sp. z o.o.

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The aim of this study was to characterize aqueous and alcoholic extracts [30%, 50% and 70% (w/v)] obtained from medicinal herbs (Calendula officinalis, Hypericum perforatum, Galium verum, and Origanum vulgare) used in traditional medicine from our country. Samples were examined for total and individual content of phenolics and antioxidant activities. The highest content of total polyphenols (9.9 +/- 0.02 mg gallic acid equivalents (GAE) L-1 extract) and antioxidant activities expressed as Trolox Equivalent Antioxidant Capacity [307.51 TEAC mmol g(-1)DW by the ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) method and 20.90 TEAC mmol g(-1) DW by the DPPH (1,1-diphenyl-2-picrylhydrazyl) method] was found in Origanum vulgare (50%) extract. Polyphenolic compounds were quantified using RP-HPLC.

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We are presenting a bienzymatic sensor for the determination of polyphenols. An ITO electrode was modified with multiwalled carbon nanotubes, and the enzymes laccase and tyrosinase were co-entrapped into a chitosan matrix. The resulting biosensor was calibrated at -50 mV (vs. the Ag/AgCl reference electrode) using rosmarinic acid, caffeic acid and gallic acid as the substrates. The new biosensor resulted in a 10.7-fold increase in response sensitivity and a considerable improvement of the detection limit (42 nM for rosmarinic acid). Fouling of the surface of the biosensor was prevented by applying the surfactant Tween 20. The data recorded in surfactant medium revealed a significant improvement of the operational stability and an enlarged linear concentration ranges (up to 12 mu M for rosmarinic acid). The sensor was used to evaluate the total phenolic content from extracts of Salvia officinalis and cultures of Basilicum callus.

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Were obtained new extracts from Salvia officinalis - 8%, 10% and 15 % (mass concentration) hydro-alcoholic extracts in 50 % ethanol - which have been processed using an original developed procedure of extract separation and concentration based on porous membranes (ultrafiltration). The extracts were characterized in terms of total polyphenols', flavones' content determination and antioxidant capacity assesement. The antioxidant capacity was assessed by two spectrophotometrical methods: 2,2-diphenylpicrlyhydrazyl (DPPH) and 2,2'- azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS). A proportionality between the polyphenols', flavones' concentrations and antioxidant capacity was observed, the highest antioxidant activity being found in case of extracts in 50% ethanol with 10% plant mass. The obtained results evidenced that the applied membranous (ultrafiltration) procedures resulted in some concentrated Salvia officinalis extracts having a high antioxidant capacity (89.89 percent of DPPH inhibition).

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Matrix assisted laser desorption-ionization time of flight (MALDI-ToF) and infrared techniques were used to study oxidative modification of low density lipoproteins (LDL), considered to have the key role in biological process that initiates and accelerates the development of cardiovascular disease. The early identification of lipoperoxidation products creates the opportunity of the efficient prevention of eventual oxidative damages. MALDI analysis of LDL subjected to in vitro oxidation process initiated by 2,2-azobis(2-amidinopropane) dihydrochloride revealed that some fragments of lipoprotein changed the molecular weight by 16 and 32 Da due to the oxygen or hydroxyl groups attachment, and peroxide or hydroperoxide formation, while Fourier Transformed Infrared studies proved that lipoprotein changes its protein secondary conformation from predominantly a-helix in predominantly beta-turn. The increase in free radicals concentration correlated to structural changes, and the presence of transitional metal ion, copper (II), in the oxidation process lead to an enhancing of the damaging effects of free radicals on lipoprotein substrate. It was shown that the toxic effects of oxidants are delayed by the presence of glutathione (10 mM), an endogenous antioxidant.

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Multiwalled carbon nanotubes with nanosized sputtered gold were used to modify a glassy carbon electrode (GCE). The substrate was characterized by scanning electron microscopy (SEM), X-ray diffraction, cyclic voltammetry and amperometry. SEM micrographs indicated an uniform coverage of the carbon nanotubes with nanosized (poly)crystalline gold. Cyclic voltammetry reveals that peak separation of the unmodified GCE in the presence of 1 mM ferricyanide is 131 mV, but 60 mV only for the modified GCE. In addition, the oxidation of NADH (1 mmol L-1 solution) begins at negative potentials (around -100 mV vs. Ag/AgCl), and the anodic peak potential (corresponding to the irreversible oxidation of NADH) is found at +94 mV. The effect of pH on the electrocatalytic activity was studied in the range from 5.4 to 8.0. The relationship between the anodic peak potential and the pH indicated a variation of -33.5 mV/pH which is in agreement with a two-electron and one-proton reaction mechanism. Amperometry, performed at either -50 or +50 mV vs. an Ag/AgCl reference electrode, indicates that the modified electrode is a viable amperometric sensor for NADH. At a working potential of +50 mV, the response to NADH is linear in the concentration range from 1 to 100 mu mol L-1, with an RSD of 6% (n = 4).

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The present paper addresses the radical scavenger properties evaluation of different extracts from plants and berries, in order to prove the feasibility of electrochemical approach to such an application. The radical scavenging properties of extracts of acclimatised Lonicerae caerulea fructus, Myrtilli fructus, Equiseti herba, Millefolii herba and Medicagini herba were evaluated using as model a long lifetime free radical 2,2'-diphenyl-1-pycrilhydrazil (DPPH). An electro-analytical method (square-wave voltammetry) devoted to the evaluation of extract properties was developed and results were confirmed using spectrochemical methods. The results were expressed in Trolox equivalent radical scavenging activity on mg dry base. In the case of Lonicera caerulea fruits the results (12385.63 mu mol TE/mg dry fruit for aqueous extract; 12455.27 mu mol TE/mg dry fruit for alcoholic extract and 3918.05 mu mol TE/mg dry fruit for total extract) proved that berries from acclimatised plant provide a high content of antioxidants.

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The aim of this paper consists in 'non-stressing' process use that, with respect to traditional plants operates under milder temperature conditions. Particular attention was devoted to investigate the possibility to purify and concentrate Viscum album extracts with a microfiltration/ultrafiltration unit, allowing the preservation of thermolabile compounds from the extracts and their antineoplastic properties examination. In vitro investigation of the HeLa cancerous cells interaction with biopreparations (extracted, separated and purified from Viscum album through successive ultrafiltrations on membranes) highlighted and quantified their cytostatic and cytotoxic impact, expressed by the inhibition of protein synthesis and cellular proliferation, by cell viability decrease and by the inhibition of cell cultures development.

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Low density lipoprotein self-assembled layers on gold support, proposed as model for oxidation studies, were subjected to oxidation processes using different oxidative agents: 2,2'-Azobis(2methylpropionamidine) dihydrochloride, atmospheric oxygen, and metal-induced oxidation. The freshly prepared and the oxidized layers were characterized by X ray photoelectron spectroscopy (XPS), Fourier-Transformed infrared spectroscopy, and Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-ToF) mass spectrometry to discriminate the effects of oxidative reagents. Data obtained from FTIR and MALDI spectra proved the lipoperoxide formation subsequent to reactive oxygen species attack and the opportunity to use the model to discriminate between oxidation toxicity.

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This paper presents the construction and surface activation of vacuum-deposed microelectrodes tested for the detection of biologically significant compounds like hydrogen peroxide and L-cysteine. It was demonstrated that the platinum working electrode surface etching by cyclic voltammetry in sulfuric acid aqueous solution lead to a significant amperometric analytical signal increase. The microelectrodes were tested as transducers for biosensor development by immobilizing acetylcholinesterase using diazonium chemistry.

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The aim of this study was to prove the efficiency of the nanofiltration process for the concentration of polyphenolic compounds from Geranium robertianum and Salvia officinalis extracts and to evaluate the extract's antioxidant activity. A lab-scale cross-flow set-up using flat-sheet configuration membrane was employed for all experiments. Two nanofiltration membranes have been used: SelRO MPF-36 (Koch membrane) and an organic-inorganic membrane (polysulfone with SBA-15-NH2). When the organic-inorganic membranes were used in the nanofiltration process, the obtained concentrated extracts proved to have higher polyphenol and flavonoid rejections, in both cases (Geranium robertianum and Salvia officinalis). The obtained values were over 88 % DPPH inhibition, for concentrated extracts, using the DPPH method. The concentrated extracts obtained after nanofiltration NF2 (organic-inorganic membrane) had the strongest scavenging activity for all extracts and almost completely inhibited DPPH absorption (92.9 % for Geranium robertianum concentrated extract and 90.1 % for Salvia officinalis concentrated extract). These features turn the studied, concentrated extracts into a good source for further medicinal applications.

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Over the past 40 years a greater attention has been focused on development of controlled and sustained drug delivery systems. The goals in designing these systems are to reduce the frequency of dosing or to increase effectiveness of the drug by localization at the site of the action, decreasing the dose required or providing uniform drug delivery. Polymers have been the keys to the great majority to design biomaterials for drug delivery systems. Chitosan, a natural biopolymer, has been extensively used for its potential in the development of biomaterials due to the polymeric cationic character and gel and film forming properties. Hydrogels preformed by chemical cross-linking or physical interactions form threedimensional, hydrophilic, polymeric networks capable of imbibing large amounts of water or biological fluid. The association of magnetic nanoparticles, which could be controlled by an exterior magnetic field and have dimensions to facilitate their penetration in cells/tissues, with hydrogel type biopolymeric shells confer them compatibility and the capacity to retain and deliver bioactive substances. In this chapter we present a synthesis of our works, from the last 5 years, in this domain of chitosan usage for synthesis of biomaterials suitable in obtaining of drug delivery systems. In our works we used mainly chitosan with slight addition of hyaluronic acid for obtaining biomaterials with controlled properties. Chitosan and hyaluronic acid are two natural biopolymers with similar structure and special biological characteristics, easily to process in porous scaffolds, films/pellicles and beads. They are biocompatible, biodegradable, promote cell migration and cell adhesion and electrostatic interact, having a great potential in the development of drug delivery systems and in tissue engineering. In a first stage, we obtained biopolymeric pellicles by casting method using mixtures of chitosan and hyaluronic acid solutions. Chitosan/hyaluronic acid pellicles crosslinked with sodium citrate could be used for enzymes immobilization on the surface or by entrapping in the polymer network. The pellicles with immobilized enzymes are stable during several months and could be used multiple times without a notable decrease of the immobilized enzymatic activity. The ultrastructure of simple chitosan pellicles, chitosan/hyaluronic acid pellicles and enzymes immobilized on chitosan/hyaluronic acid pellicles were examined by confocal scanning laser microscopy. More recently, in other works, we developed a new system based on magnetic nanoparticles covered in a layer-by-layer technique with a biocompatible hydrogel from chitosan and hyaluronic acid capable of vectoring support for biologic active agents (Lasparaginase, protease inhibitor, e.g.). Characterization of size and morphology of the obtained hydrogel-magnetic nanoparticles with entrapped L-asparaginase/protease inhibitor was made using dynamic light scattering method, transmission electron microscopy and confocal microscopy. The structure of magnetic nanoparticles coated with hydrogel was characterized by Fourier transformed infrared spectroscopy. The biocompatibility of nanoparticles was evaluated and also the interactions with microorganisms. The characteristics of developed pellicles and nanocomposite materials made them suitable to be used for medical or biotechnological purposes. © 2011 by Nova Science Publishers, Inc. All rights reserved.

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This work present a phytochemical qualitative study regarding certain classes of compounds: tannins, amino acids, terpenoides, sterols, triterpenes, flavonoids, reducing agents, saponins, alkaloids in Symphytum officinalis (10% mass concentration) extracts in EtOH 50% and MeOH 50%. The allantoin - a bioactive compound characteristic for the comfrey - was quantitatively determined. The extracts were further concentrated through membranous procedures (ultrafiltration) using Millipore ultrafiltration membranes with 5000 daltoni (Da) cut-off (molecular mass exclusion). The analytical determinations were carried out in the initial extracts, permeates and concentrated solutions.

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A new modified glassy carbon electrode (GCE) based on a synthesized N-(2-aminoethyl)-4,4'-bipyridine (ABP) was developed for the determination of Ag(I) by differential pulse voltammetry (DPV). ABP was covalently immobilized on GC electrodes surface using 4-nitrobenzendiazonium (4-NBD) and glutaraldehyde (GA). The Ag(I) ions were preconcentrated by chemical interaction with bipyridine under a negative potential (-0.6 V); then the reduced ions were oxidized by differential pulse voltammetry and a peak was observed at 0.34 V. The calibration curve was linear in the concentration range from 0.05 μM to 1 μM Ag(I) with a detection limit of 0.025 μM and RSD = 3.6%, for 0.4 μM Ag(I). The presence of several common ions in more than 125-fold excess had no effect on the determination of Ag(I). The developed sensor was applied to the determination of Ag(I) in water samples using a standard addition method. © 2010 by the authors.

Abstract

A new modified glassy carbon electrode (GCE) based on a synthesized N-(2-aminoethyl)-4,4'-bipyridine (ABP) was developed for the determination of Ag(I) by differential pulse voltammetry (DPV). ABP was covalently immobilized on GC electrodes surface using 4-nitrobenzendiazonium (4-NBD) and glutaraldehyde (GA). The Ag(I) ions were preconcentrated by chemical interaction with bipyridine under a negative potential (-0.6 V); then the reduced ions were oxidized by differential pulse voltammetry and a peak was observed at 0.34 V. The calibration curve was linear in the concentration range from 0.05 mu M to 1 mu M Ag(I) with a detection limit of 0.025 mu M and RSD = 3.6%, for 0.4 mu M Ag(I). The presence of several common ions in more than 125-fold excess had no effect on the determination of Ag(I). The developed sensor was applied to the determination of Ag(I) in water samples using a standard addition method.

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Background. In the present study the antioxidant properties were investigated of the medicinal plants Salvia officinalis L. (Labiaceae family) and Viscum album L. (Loranthaceae), both of them known for a long time as a remedy in the traditional medicine. The aim of this study was to prove the efficiency of ultrafiltration process for the concentration of herbs extracts and to evaluate the concentrate's antioxidant activity. Material and methods. The extracts were prepared by maceration, using different solvents. After filtering the extract through Isolab quantitative filter paper medium, each of the filtrates was processed by microfiltration (MF; Millipore filters with 45 mu m), followed by ultrafiltration (UF). The regenerated cellulose (Millipore), polysulfone and polyacrylonitrile ultrafiltration membranes were used in the experiment. The initial extracts and samples of permeate and retentate after ultrafiltration of extracts have been characterized by determination of the protein total and total phenolic content. Standard methods like ABTS and DPPH assay are used to measure the antioxidant activity. Results. For the three types of tested membranes: Millipore, PSF and PAN, PAN membrane proves to have the greatest efficiency since it shows the highest permeate flux and the greatest retention degree for bioactive compounds. The concentrated extracts obtained after ultrafiltration with polyacrylonitrile membrane had the strongest scavenging activity for all extracts. Conclusions. The results of this study has revealed that the concentrated extracts have a very high radical scavenging activity (TEAC values for sage hydro-alcoholic concentrated extracts in range 351.87-479.04 mu mol Trolox/mL extract and for mistletoe concentrated extract E2 in range 345.14-426.18 mu mol Trolox/mL extract; the DPPH inhibition values was over 85% for S. officinalis concentrated extracts and ranges between 66.2% and 88.2% DPPH inhibition for V. album concentrated), therefore can be considered as a good source for further medicinal applications.

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The paper reports the performance of polysulfone-polyaniline composite membranes in medicinal plants concentration, by means of the ultrafiltration process. The effect of operating pressure, raw material concentration on permeate flux, and some biological compounds concentration in permeate and concentrate were analyzed. The aim of this article was to compare the performances of the ultrafiltration process. using the polysulfone and the polysulfone-polyaniline membranes for the concentration of Salvia officinale extracts. The bioactive compounds (reducing sugars, proteins and polyphenols) have been characterized by UV-VIS spectrometry, using specific methods for each (compounds) ones. The ultrafiltration process' performance can be increased using a polysulfone-polyaniline membrane. The experimental results showed higher efficacy of polysulfone-polyaniline composite membranes versus polysulfone membrane for the concentration of plant extracts.

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Soilless cultures are nowadays an important tool for both (i) large scale synthesis of pharmaceutically active products, and for (ii) ex situ conservation of endemic and/or endangered plants that are also of horticultural importance. (i) Epilobium hirsutum explants were grown on both solid-and shaken liquid-medium, for multiplication and for greater biomass production, respectively. Secondary metabolites extracted from the biomass thus obtained were mainly polyphenols (galloylglucose and monomeric and dimeric ellagitannins), which are pharmaceutically important in prostate adenoma treatment, among others. Seedlings' dry biomass production increased from 1.5 g DW L-1 to 22 g DW L-1 after 15 days when nodes/inocula were grown on shaken liquid-medium, in light, and using different phytohormonal conditions. Secondary metabolites yield (polyphenols) of seedlings was equal to or higher (under some conditions) than for intact plants grown normally, in soil, under normal conditions. (ii) In vitro conservation on solid media resulted in a collection of 12 species that are endemic and/or endangered for Europe, and 7 species for Romania, respectively. Included in this collection are: Dianthus spiculifolius, D. nardiformis, D. henteri, D. glacialis subsp. gelidus, D. haematocalyx subsp. pindicola, D. seguieri, D. sternbergii, Achillea pyrenaica, Paradisea liliastrum. Dianthus petraeus subsp. simonkaianus was the species with the best multiplication rate (110 shoots/inoculum).

Abstract

Background. In the present study the antioxidant properties were investigated of the medicinal plants Salvia officinalis L. (Labiaceae family) and Viscum album L. (Loranthaceae), both of them known for a long time as a remedy in the traditional medicine. The aim of this study was to prove the efficiency of ultrafiltration process for the concentration of herbs extracts and to evaluate the concentrate's antioxidant activity. Material and methods. The extracts were prepared by maceration, using different solvents. After filtering the extract through Isolab quantitative filter paper "medium", each of the filtrates was processed by microfiltration (MF; Millipore filters with 45 μm), followed by ultrafiltration (UF). The regenerated cellulose (Millipore), polysulfone and polyacrylonitrile ultrafiltration membranes were used in the experiment. The initial extracts and samples of permeate and retentate after ultrafiltration of extracts have been characterized by determination of the protein total and total phenolic content. Standard methods like ABTS and DPPH assay are used to measure the antioxidant activity. Results. For the three types of tested membranes: Millipore, PSF and PAN, PAN membrane proves to have the greatest efficiency since it shows the highest permeate flux and the greatest retention degree for bioactive compounds. The concentrated extracts obtained after ultrafiltration with polyacrylonitrile membrane had the strongest scavenging activity for all extracts. Conclusions. The results of this study has revealed that the concentrated extracts have a very high radical scavenging activity (TEAC values for sage hydro-alcoholic concentrated extracts in range 351.87-479.04 μmol Trolox/mL extract and for mistletoe concentrated extract E2 in range 345.14-426.18 μmol Trolox/mL extract; the DPPH inhibition values was over 85% for S. officinalis concentrated extracts and ranges between 66.2% and 88.2% DPPH inhibition for V. album concentrated), therefore can be considered as a good source for further medicinal applications. © Copyright by Wydawnictwo Uniwersytetu Przyrodniczego w Poznaniu.

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The flour obtained from germinated wheat has a low quality and may be identified by its increased content of a specific marker: a toxic lectin named wheat germ agglutinin (WGA). Quartz crystal microbalance was used to study the lectin-carbohydrate bioaffinity interactions. Sensors for two plant lectins: Concanavalin A (Con A) and WGA were obtained by immobilizing glucose on gold coated piezoelectric quartz crystals via thiol bonds. The limit of detection was 0.1 μg/mL for Con A and 0.5 μg/mL for WGA. The proposed method was sensitive enough to detect the biologically active WGA from whole meal flour samples produced using three types of wheat before and after 36 h of germination. The WGA amount in germinated wheat was increased by 17-36.9%. The obtained WGA recoveries from spiked samples were between 88.7 and 110.6%. The analysis method may be adapted for the determination of biologically active lectins from nutritional supplements based on the plant extracts. © Springer-Verlag 2009.

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Symphytum officinale L (Boraginaceae) species are currently used in the Romanian traditional medicine to treat different human and animal disease. being also active in certain cancer forms. This work's aim consists in obtaining of Symphytum officinale concentrated extracts by using performance membrane processes, aqueous extracts prepared were concentrated by tangential flow ultrafiltration with a Koch Laboratory Cell CF-1 membrane. The cytostatic activity of the total plant extracts were studied on HeLa cells culture. By comparison to the bystander value of 1001116, we noticed that in vitro treatment of HeLa neoplasic cells with these concentrated extracts determined a mitoinhibitory effect with statistical and cytostatical significant amplitude. These values were of almost 57,6% for Symphytum officinale.

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