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A simple and rapid differential pulse voltammetric (DPV) method using a single-use electroactivated pencil graphite electrode (PGE*) is proposed for the rapid screening of the total content of polyphenolics (TCP) with intermediate antioxidant power (AOP) in grapefruit peel and fresh juice. The results were compared and correlated with those provided by the HPLC-DAD-MS method. NG voltammetric behavior at PGE* was studied by cyclic voltammetry and an oxidation mechanism was suggested. The experimental conditions (type of PGE, electroactivation procedure, pH, nature and concentration of supporting electrolyte) for NG DPV determination were optimized. The NG peak current varied linearly with the concentration in the ranges 1.40 x 10(-6)-2.00 x 10(-5) and 2.00 x 10(-5)-1.40 x 10(-4) mol/L NG and a limit of detection (LoD) of 6.02 x 10(-7) mol/L NG was attained. The method repeatability expressed as relative standard deviation was 7.62% for the concentration level of 2.00 x 10(-6) mol/L NG. After accumulation for 240 s of NG at PGE* the LoD was lowered to 1.35 x 10(-7) mol/L NG, the linear range being 6.00 x 10(-7)-8.00 x 10(-6) mol/L NG. The developed electrochemical system was successfully tested on real samples and proved to be a cost-effective tool for the simple estimation of the TCP with intermediate AOP in citrus fruits.

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Hesperidin (HESP) is a plant bioflavonoid found in various nutritional and medicinal products. Many of its multiple health benefits rely on the compound's antioxidant ability, which is due to the presence of oxidizable hydroxyl groups in its structure. Therefore, the present study aimed to investigate the electrochemical behavior of HESP at a cheap, disposable pencil graphite electrode (PGE) in order to develop rapid and simple voltammetric methods for its quantification. Cyclic voltammetric investigations emphasized a complex electrochemical behavior of HESP. The influence of the electrode material, solution stability, supporting electrolyte pH, and nature were examined. HESP main irreversible, diffusion-controlled oxidation signal obtained at H type PGE in Britton Robinson buffer pH 1.81 was exploited for the development of a differential pulse voltammetry (DPV) quantitative analysis method. The quasi-reversible, adsorption-controlled reduction peak was used for HESP quantification by differential pulse adsorptive stripping voltammetry (DPAdSV). The linear ranges of DPV and DPAdSV were 1.00 x 10(-7)-1.20 x 10(-5) and 5.00 x 10(-8)-1.00 x 10(-6) mol/L with detection limits of 8.58 x 10(-8) and 1.90 x 10(-8) mol/L HESP, respectively. The DPV method was applied for the assessment of dietary supplements bioflavonoid content, expressed as mg HESP.

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This work proposes a novel method for determining the composition of mixtures of natural polyphenolic compounds: caffeic acid, gallic acid, ellagic acid, rosmarinic acid and quercitrin in plants. The method is based on the formation of colored spots by these compounds upon reaction with nano-oxides of Al2O3, ZnO, MgO, CeO2, TiO2 and MoO3 impregnated on filter paper and constituting a colorimetric sensor array (CSA). The image of the colored spots was analyzed and the intensity of the blue colour (BCI) component has shown maximum sensitivity in relation to phenolic compounds. The inverse of BCI was linearly correlated with the logarithm of the individual phenolic compound concentrations. Chemometric analysis by partial least squares regression (PLSR) of 1/BCI values for 24 synthetic mixtures of the 5 phenolic compounds measured with the colorimetric sensor array has demonstrated good correlation between the actual and the predicted concentration of quercitrin. For the other phenolic compounds, the colors measured with the colorimetric sensor array were greatly influenced by the concentrations of the other components in the mixture. The method was applied to the determination of quercitrin in medicinal teas and the results were compared to those obtained by HPLC. The discussion of the results emphasizes possible interferences in the tea samples. While further optimization of the colorimetric sensor array-based method appears necessary, tailored to the particular targeted application in real samples, the proposed method for polyphenol determination has advantages that include simplicity, low cost, and portability.

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The electrochemical behaviour of the flavonoid naringenin (NGN) was investigated for the first time by cyclic voltammetry (CV), using a disposable electroactivated pencil graphite electrode (PGE*). In this electrochemical sensor, NGN is irreversibly oxidized, giving rise to two pH-dependent peaks due to mixed (diffusion- and adsorption-controlled) electrode processes involving the same number of electrons and protons, namely two and one, respectively. Exploiting these peaks, differential pulse voltammetry (DPV) and square wave voltammetry (SWV) at PGE* in 0.05 mol L-1 potassium hydrogen phthalate were applied for quantitative determination of NGN. The new proposed methods presented linear ranges covering more than three orders of magnitude (7.86 x 10(-8) to 1.82 x 10(-4) mol L-1 NGN for DPV and 7.50 x 10(-8) to 1.00 x 10(-4) mol L-1 NGN for SWV) and low limits of detection (LoD) and quantification (LoQ) (LoD = 3.06 x 10(-8) mol L-1, LoQ = 1.02 x 10(-7) mol L-1 NGN for DPV and LoD = 4.40 x 10(-8) mol L-1, LoQ = 1.11 x 10(-7) mol L-1 NGN for SWV), similar to or better than those reported in the literature. The developed voltammetric methods were applied with good results to determine the intermediate antioxidant power polyphenolics content expressed as mg naringenin equivalent per L grapefruit juice.

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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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The electrochemical behaviour of the flavonoid naringenin (NGN) was investigated for the first time by cyclic voltammetry (CV), using a disposable electroactivated pencil graphite electrode (PGE∗). In this electrochemical sensor, NGN is irreversibly oxidized, giving rise to two pH-dependent peaks due to mixed (diffusion- and adsorption-controlled) electrode processes involving the same number of electrons and protons, namely two and one, respectively. Exploiting these peaks, differential pulse voltammetry (DPV) and square wave voltammetry (SWV) at PGE∗ in 0.05 mol L -1 potassium hydrogen phthalate were applied for quantitative determination of NGN. The new proposed methods presented linear ranges covering more than three orders of magnitude (7.86 × 10 -8 to 1.82 × 10 -4 mol L -1 NGN for DPV and 7.50 × 10 -8 to 1.00 × 10 -4 mol L -1 NGN for SWV) and low limits of detection (LoD) and quantification (LoQ) (LoD = 3.06 × 10 -8 mol L -1 , LoQ = 1.02 × 10 -7 mol L -1 NGN for DPV and LoD = 4.40 × 10 -8 mol L -1 , LoQ = 1.11 × 10 -7 mol L -1 NGN for SWV), similar to or better than those reported in the literature. The developed voltammetric methods were applied with good results to determine the intermediate antioxidant power polyphenolics content expressed as mg naringenin equivalent per L grapefruit juice. © 2018 The Royal Society of Chemistry.

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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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Background: Arum hygrophilum is a traditional medicinal plant indigenous to Jordan. The present study explores its phytochemistry, antioxidative, antidiabesity, and antiproliferative potentialities. Materials and Methods: Column chromatography and HPLC-MS analysis were used for its phytochemical evaluation. Using leaf crude water and ethanol extracts, the antioxidative capacities, their modulation of pancreatic beta-cell proliferation, and insulin secretion as well as glucose diffusion and enzymatic bioassays were evaluated. Results: Three flavonoids (luteolin, isoorientin, and vitexin) and beta-sitosterol have been isolated and their structures determined. HPLC-MS analysis of the ethanol extract further revealed the presence of caffeic, ferulic, gallic, and rosmarinic acids and quercetine-3-O-rhamnoside. The ethanol extract exhibited DPPH and ABTS radical scavenging and antioxidative capacities. A. hygrophilum (1), vitexin (2), and rosmarinic acid (3) inhibited pancreatic lipase (PL) dose dependently with PL-IC50 (mu g/ mL) values in an ascending order: (3); 51.28 +/- 7.55 < (2); 260.9 +/- 21.1 < (1); 1720 +/- 10. Comparable to GLP-1-enhanced beta-cell proliferation in 2-day treatment wells, a dose-dependent augmentation of BrdU incorporation was obtained with the A. hygrophilum aqueous extract (AE) (0.5 and 1 mg/ mL, with respective 1.33-and 1.41-folds, P < 0.001). A. hygrophilum AE was identified as an inhibitor of alpha-amylase/alpha-glucosidase with IC50 value of 30.5 +/- 2.1 mg/mL but lacked antiproliferative effects in colorectal cancer cell lines (HT29, HCT116, and SW620) and insulinotropic effects in beta-cell line MIN6. Conclusion: A. hygrophilum extracts inhibited gastrointestinal enzymes involved in carbohydrate and lipid digestion and absorption.

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An optical/amperometric biosensor based on algal cells immobilized in calcium alginate gel was developed. Various Chlamydomonas reinhardtii strains mutated at the level of photosynthetic D1 protein were used as biomediators to quantify the capacity of the carotenoid xanthophylls to protect the photosynthetic apparatus from photoinhibition. The highly sensitive/selective biosensor was used for studies on cell physiology aimed to determine the antioxidant and light filtering effects of the xanthophyll astaxanthin. The biosensor was proved to be suitable for the determination of the exogenous supplied astaxanthin, showing in a short time a reliable response with a detection limit of 3 mu M. This technique revealed the photoprotective effect of astaxanthin-enriched extracts of Haematococcus pluvialis in algal cells. The results suggest that in algae astaxanthin exploits both filtering and antioxidant effects at different light intensities. This bioinspired approach can provide new insights into biological, biomedical, environmental and agricultural research applications and nutraceutical studies. (C) 2016 Elsevier B.V. All rights reserved.

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Frequent occurrence of food contamination, growing concern about public safety, and the adoption of more stringent legislations have promoted research efforts in the agrifood industry as well as in environmental monitoring, attempting to guarantee improvements in food quality and safety. In addition, the increasing demand for sustainable agriculture has led to the introduction of novel processing methods for raw materials to achieve stable foods. For this reason, it is imperative that efficient and reliable diagnostic tools be developed to detect potential hazards in agriculture and for food safety. In this context, biosensor technology represents the cutting -edge frontier in the agrifood and environmental fields. Indeed, smart monitoring of chemical contaminants (i.e., pesticides, heavy metals, toxins, allergenic compounds, and food additives) represents one of the evolving issues challenging the assessment of food quality and safely. Progress in multianalyte screening, functional materials, microlluidics and nanotechnology is amplifying the potential market of biosensors, making this technology more competitive in comparison with conventional lab -based procedures in terms of speed of response and operational held usage. However, despite the large number of publications and patents on biosensors for food analysis, only a few systems have been able to reach the market. Among the main drawbacks to he faced are the limited lifetime of biological components, mass production, as well as portability. In this chapter, current and future trends in analytical diagnostic tools are discussed, with the aim of promoting a deeper cooperation between research and industries and encouraging the use of biosensing technology as a more attractive option for the commercial sector.

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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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It is studied a batch analytical method based on the system Co(II)EDTA/luminol/H2O2 for the determination of antioxidant capacity of different types of sample. The method is based on the oxidation and chemiluminescence of luminol under the influence of reactive oxygen species produced in a Fenton type reaction of hydrogen peroxide with Co(II). The antioxidants from a sample react with the reactive oxygen species and decrease the chemiluminescence signal. It was drawn a calibration graph by plotting the ratio of chemiluminescence intensity in the absence and in the presence of an antioxidant and the concentration of a standard antioxidant (gallic acid). The calibration graph is linear in the domain 10(-6) - 10(-4) M galic acid. The method was applied for the analysis of three types of fruit juices. It has been done a comparison between the results for antioxidant capacity determination obtained with the developed method and the literature data for similar types of samples. The acuracy of the method was verified by using standard addition method.

Abstract

Arum dioscoridis and A. palaestinum (Araceae) are indigenous plant species in Jordan. HPLC-MS analysis of A. dioscoridis revealed the presence of apigenin, luteolin, quercetin, quercetin-3-O--glucoside, vitexin, isoorientin, esculin, and caffeic and ferulic acids. Both Arum spp., influenced gastrointestinal carbohydrate and lipid digestion and absorption. Orlistat inhibited dose dependently and highly substantially pancreatic lipase (PL) in vitro. Similar to orlistat, Arum species aqueous extracts (AEs), apigenin, caffeic acid and esculin exhibited a concentration related PL inhibition. Comparable to acarbose, dual inhibition of -amylase/-glucosidase was observed for both Arum species. Like guar gum, A. dioscoridis AE minimised substantially area under 24h glucose curve. Acute starch-induced postprandial hyperglycaemia in overnight fasting rats was highly significantly (p<0.001) decreased by A. dioscoridis AE. A. palaestinum could not perform effectively in either starch- or glucose-fed fasting rats. No antiproliferative effects against colorectal cancer cell lines HT29, HCT116 and SW620 were detected for tested Arum spp. [GRAPHICS] .

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Endocrine disrupting chemicals (EDCs) are harmful, xenobiotic compounds requiring a multi-tiered analytical approach for a reliable management. Although worth efforts worldwide, comprehensive EDCs monitoring and risk-assessment still require improvements. This article covers possible risks for public health due to EDCs exposure, and revises the maturity reached in different analytical detection fields, with a special focus on biosensor technology. Among validated laboratory-techniques, hyphenated mass spectrometry-based chromatography provides high selectivity and multi-analyte detection, while in vitro bioassays enable reliable toxicological testing. However, none of these methods is suitable for fast in field, continuous or semi-continuous operations. Due to advances in material science and synthetic biology, now biosensor technology holds the promise to close this gap and, although not included yet in routinely screening programs, fulfill the necessary requirements to sustain a coherent and global strategy to assess the state of environmental pollution. (C) 2016 Elsevier B.V. All rights reserved.

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A Surface Plasmon Resonance (SPR) sensor for the quantitation of lysozyme dimer in monomer-dimer mixtures, reaching a detection limit of 1.4 nM dimer, has been developed. The sensor is based on an aptamer which, although developed for the monomeric form, binds also the dimeric form but with a strikingly different kinetics. The aptasensor was calibrated using a dimer obtained by cross-linking. Sensorgrams acquired with the aptasensor in monomer-dimer mixtures were analysed using Principal Components Analysis and Multiple Regression to establish correlations with the dimer content in the mixtures. The method allows the detection of 0.1-1% dimer in monomer solutions without any separation. As an application, the aptasensor was used to qualitatively observe the initial stages of aggregation of lysozyme solutions at 60 degrees C and pH 2, through the variations in lysozyme dimer amounts. Several other methods were used to characterize the lysozyme dimer obtained by cross-linking and confirm the SPR results. This work highlights the versatility of the aptasensor, which can be used, by simply tuning the experimental conditions, for the sensitive detection of either the monomer or the dimer and for the observation of the aggregation process of lysozyme. (C) 2016 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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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.

Abstract

Biosensors are powerful tunable systems able to switch between an ON/OFF status in response to an external stimulus. This extraordinary property could be engineered by adopting synthetic biology or biomimetic chemistry to obtain tailor-made biosensors having the desired requirements of robustness, sensitivity and detection range. Recent advances in both disciplines, in fact, allow to re-design the configuration of the sensing elements - either by modifying toggle switches and gene networks, or by producing synthetic entities mimicking key properties of natural molecules. The present review considered the role of synthetic biology in sustaining biosensor technology, reporting examples from the literature and reflecting on the features that make it a useful tool for designing and constructing engineered biological systems for sensing application. Besides, a section dedicated to bioinspired synthetic molecules as powerful tools to enhance biosensor potential is reported, and treated as an extension of the concept of biomimetic chemistry, where organic synthesis is used to generate artificial molecules that mimic natural molecules. Thus, the design of synthetic molecules, such as aptamers, biomimetics, molecular imprinting polymers, peptide nucleic acids, and ribozymes were encompassed as products of biomimetic chemistry. (C) 2015 Elsevier B.V. All rights reserved.

Abstract

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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Hypercholesterolemia is a predominant risk factor for atherosclerosis and associated with coronary and cerebrovascular diseases. The global incidence of hypercholesterolemia is rapidly increasing. Adiantum capillus veneris L. (Adiantaceae) has been reported as herbal medicine for diverse ailments in Jordan. However, its alleged benefits and action mechanisms remain elusive. Thus the present study aimed to identify the phenolic constituents of A. capillus veneris by LC-MS and to evaluate the chronic effect of its water extract on 10-weeks high cholesterol diet (HCD)-fed rats serum lipid profile and atherogenic index. Antioxidant potential is also assessed. Rats were divided into four groups of 6 rats each. Group 1 was kept on stand diet; the remaining three groups were high-cholesterol fed for ten weeks. On week 7 onwards; Group 3 was atorvastatin 10 mg/Kg b.wt- treated, while group 4 was supplemented daily with A. capillus veneris 500 mg/Kg b.wt. HPLC-MS analyses revealed the presence of ellagic acid (5.48 mg/g), rutin (4.77 mg/g), quercetin-3-O-glucoside (3.96 mg/g), ferulic acid (3.88 mg/g), gallic acid (3.44 mg/g), caffeic acid (1.55 mg/g), epicatechine (1.34 mg/g) and quercetine (0.43 mg/g). Crude extracts of the aerial parts exhibited potent antioxidant activity by ORAC, ABTS and DPPH assays (2184.95 +/- 109.3, 762.50 +/- 38.1, and 337.07 +/- 16.9 Trolox equivalent nmol/mg, respectively). Exceeding atorvastatin 10 mg/Kg b.wt effectiveness (p<0.05, n=6 rats/group), 10-week administration of A. capillus veneris extract in HCD-fed rats decreased highly significantly the total cholesterol (TC), LDL and VLDL serum levels. VLDL serum levels in both intervention groups were substantially (p<0.001) and comparably decreased. Neither treatment could affect HDL serum levels. Besides, atherogenic index parameter of TC/HDL was normalized in A. capillus veneris-treated rats. A. capillus veneris can be considered as potential candidate for management of hypercholesterolemia and its atherosclerotic complications.

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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.

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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).

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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

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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.

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Context: Verbascum phlomoides L. (Scrophulariaceae) (mullein) used in the European folk medicine due to its anti-inflammatory and soothing action on the respiratory tract is thoroughly documented in handbooks and scientific literature. Nevertheless, information regarding the influence of the polyphenol content on pharmacological activity is scarce. Objective: This study explored the antioxidant and anti-inflammatory potential of V. phlomoides polyphenol-rich extract. Materials and methods: Dried mullein flowers (200 g) were subjected to water extraction (60 degrees C, 2 h, herb/solvent ratio = 1/10 m/v) and further to n-butanol partition. Total phenolics were spectrophotometrically determined and specific compounds were evaluated by HPLC. The antioxidant activity was assessed by the 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) assay. The anti-inflammatory potential of the extract (50-200 mg/mL) was evaluated in vitro by ELISA measurement of ICAM-1 expression in TNF-alpha-stimulated endothelial cells and in vivo by the rat paw edema assay. Results: The mullein extract contained 4.18% total polyphenols expressed as gallic acid. The main components identified by HPLC were: rosmarinic acid (14.93 mg/g), caffeic acid (39.96 mg/g), ferulic acid (29.61 mg/g) and quercetin (17.29 mg/g). Acteoside was not detected; aucubin was detected in traces (0.028 mg/g). Depending on concentration, the extract exerted scavenging activity on DPPH radical (EC50 7.09 mg/mL), significantly inhibited TNF-alpha-induced ICAM-1 expression by 55-58.8% on human umbilical vein endothelial cells at 100 and 200 mg/mL, but failed to reduce egg-white-induced rat paw edema. Discussion and conclusion: Mullein polyphenols play an important role in exerting the antioxidant effect but have a weak influence on anti-inflammatory activity that is correlated, probably, to a higher content of iridoids and phenylethanoids.

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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.

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A novel aptamer and surface plasmon resonance (SPR)-based sensor was developed for the label-free detection of lysozyme. The aptasensor is characterised by a detection limit of 1 mg mL(-1) and a linear range of 5-50 mu g mL(-1). As an application, we examined the usefulness of the aptasensor for monitoring the early stages of the aggregation of lysozyme. It was surprisingly found that, despite a significant decrease in monomer content during aggregation, the response of the aptasensor for protein solutions aged for 12 hours was similar to that for the fresh protein. To correlate the results obtained with the aptasensor with the composition of lysozyme solutions at various time points, we examined them in detail by atomic force microscopy (AFM), thioflavin T fluorescence, size-exclusion chromatography (SEC) and Matrix Assisted Laser Desorption Ionisation Time of Flight Mass Spectrometry (MALDI-TOF-MS). All methods together indicated that during the initial hours of aggregation, the protein solutions contained small lysozyme oligomers (mainly dimers) and decreasing amounts of monomers. Our results thus suggest that the aptamer also recognizes lysozyme dimers/oligomers. A higher non-specific binding was observed for the aggregated lysozyme at the surface of the aptasensor as compared to the native protein. This was attributed to the hydrophobic patches which are exposed by the unfolded lysozyme and/or oligomer species, allowing for different adsorption and organisation at the surface of the aptasensor. This hypothesis is supported by square wave voltammetry (SWV) studies using solutions of aggregated lysozyme. A higher electrochemical signal due to the direct oxidation of tyrosine/tryptophan residues was observed for aged protein solutions as compared to the fresh solution, indicative of an increased number of such exposed electroactive residues and of overall increased surface hydrophobicity of the protein. Our work presents a label-free lysozyme aptasensor that is useful not only for the detection of the protein monomer but also for observing the onset of aggregation. The approach can be extended to other proteins which are prone to aggregation.

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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.

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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.

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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.

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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.

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The unicellular green alga Chlamydomonas reinhardtii was exploited as bio-sensing element for the construction of an electrochemical whole-cell based biosensor to detect herbicides in water samples. To preserve the algal photosynthetic functionality, C. reinhardtii cells were entrapped in an alginate gel directly onto the surface of commercial screen-printed electrodes. Cyclic voltammetry (CV) measurements indicated the higher performance of screen-printed carbon nanotube electrodes compared to graphite and gold as working materials. Moreover, it provided insights into the electrochemical reactions occurring at the electrode/algal cells interface, and indicated the optimum buffer pH (pH 7.0) and potential values -(0.7 +/- 0.03) V vs. Ag/AgCl reference electrode to maximize current signals in chronoamperometry (CA) experiments. Electrodes with different number of cells and related chlorophyll content were tested by CA to optimize the electrochemical signal in terms of peak current intensity and signal to noise ratio. The oxygen reduction signal originated from the algal activity in response to red LEDs light exposure was monitored by amperometry, and the bio-sensing element response was expressed as a ratio between the current intensities registered in the absence and in the presence of herbicides. As competitive inhibitors of the plastoquinone (Q(B)) binding to the reaction centre D1 protein, triazine and urea-type herbicides block the photosynthetic electron transport leading to a reduction of the biosensor output currents in a concentration-dependent manner. For linuron and simazine the limits of detection were 6 x 10(-9) and 9 x 10(-8) M, respectively, while the inhibition constant values (I-50) were (1.2 +/- 0.1) x 10(-7) and (2.3 +/- 0.2) x 10(-6) M. The operational half-life of the bio-recognition element lasted approximately 9 h, while room temperature storage stability tests indicated a 2 and 24% signal loss after 3 and 20 days, respectively. The inhibition of the biosensor photosynthetic activity was irreversible at low herbicide concentrations, and highly reversible at medium-high doses. These results were discussed considering the presence in the Photosystem II pigment-protein complex of two herbicide binding niches with different binding affinities. Beyond introducing a promising prototype for commercial applications, this research shed light on current functional issues related to the not yet fully explored plastoquinone/herbicide binding site. (C) 2013 Elsevier B.V. All rights reserved.

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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.

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The Strategy for the Danube region, presently developed by the Danube countries under the guidance of the European Commission, focuses on 4 pillars (connectivity, protecting the environment, building prosperity and strengthening the Danube region).Within the strategy frame the major aims are to implement an integrative policy in the region and to enhance cross-border cooperation as a way to achieve the EU overarching goal of sustainability (COM 400, 2009). Reaching the peak at the beginning of 2000, since in June 2011 the European Commission adopted the mentioned Strategy for the Danube region, the Danube river and its related issues were a matter of concern in the last centuries. The present notes are addressing the objective of creating a new structure able to support the regional efforts in the Danube Strategy implementation.

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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 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 Strategy for the Danube region, presently developed by the Danube countries under the guidance of the European Commission, focuses on 4 pillars (connectivity, protecting the environment, building prosperity and strengthening the Danube region). Within the strategy frame the major aims are to implement an integrative policy in the region and to enhance cross-border cooperation as a way to achieve the EU overarching goal of sustainabiliry (COM 400, 2009). Reaching the peak at the beginning of 2000, since in June 2011 the European Commission adopted the mentioned Strategy for the Danube region, the Danube river and its related issues were a matter of concern in the last centuries. The present notes are addressing the objective of creating a new structure able to support the regional efforts in the Danube Strategy implementation.

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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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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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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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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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The EU project Nutra-Snack established an integrated scientific and technological framework to introduce conventional and new biotechnologies into the nutraceutical industry. The purpose was to promote novel ready-to-eat snacks enriched with natural antioxidant/radical-scavenging compounds. Enhancement of valuable compounds production in plant cells and in vitro cultures were achieved by different elicitation strategies, and exhaustive metabolites profiling obtained by high-resolution analytical techniques. Finally, innovative enzyme-based biosensors were developed for food products functional activity and safety properties assessment. This review provides an overview of the technologies selected, integrated and tested in NUTRA-SNACK and recent literature strengthening integrated approaches in modern food process manufacturing.

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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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