Mutagenic activity removal of selected disperse dye by photoeletrocatalytic treatment

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Double-Tagging Polymerase Chain Reaction with a Thiolated Primer and Electrochemical Genosensing based on Gold Nanocomposite Sensor for Food Safety

A novel material for electrochemical biosensing based on rigid conducting gold nanocomposite (nano-AuGEC) is presented. Islands of chemisorbing material (gold nanoparticles) surrounded by nonreactive, rigid, and conducting graphite epoxy composite are thus achieved to avoid the stringent control of surface coverage parameters required during immobilization of thiolated oligos in continuous gold surfaces. The spatial resolution of the immobilized thiolated DNA was easily controlled by merely varying the percentage of gold nanoparticles in the composition of the composite. As low as 9 fmol (60 pM) of synthetic DNA were detected in hybridization experiments when using a thiolated probe. Moreover, for the first time a double tagging PCR strategy was performed with a thiolated primer for the detection of Salmonella sp., one of the most important foodborne pathogens affecting food safety. Ibis assay was performed by double-labeling the amplicon during the PCR with a -DIG and -SH set of labeled primers. The thiolated end allows the immobilization of the amplicon on the nano-AuGEC electrode, while digoxigenin allows the electrochemical detection with the antiDIG-HRP reporter in the femtomole range. Rigid conducting gold nanocomposite represents a good material for the improved and oriented immobilization of biomolecules with excellent transducing properties for the construction of a wide range of electrochemical biosensors such as immunosensors, genosensors, and enzymosensors.

Comparison of oxidation efficiency of disperse dyes by chemical and photoelectrocatalytic chlorination and removal of mutagenic activity

Degradation of Disperse Orange 1, Disperse Red 1 and Disperse Red 13 dyes has been performed using electrochemical oxidation on Pt electrode, chemical chlorination and photoelectrochemical oxidation on Ti/TiO(2) thin film electrodes in NaCl or Na(2)SO(4) medium. 100% discoloration was obtained for all tested methods after 1 h of treatment. Faster color removal was obtained by photoelectrocatalytic oxidation in 0.1 mol L(-1) NaCl pH 4.0 under UV light and an applied potential of +1.0V (vs SCE reference electrode), which indicates also values around 60% of TOC removal. The conventional chlorination method and electrochemical oxidation on Pt electrode resulted in negligible reduction of TOC removal. All dyes showed positive mutagenic activity in the Salmonella/microsome assay with the strain TA98 in the absence and presence of S9 (exogenous metabolic activation). Nevertheless, there is complete reduction of the mutagenic activity after 1 h of photoelectrocatalytic oxidation, suggesting that this process would be good option to remove disperse azo dyes from aqueous media. (C) 2008 Elsevier Ltd. All rights reserved.

Chlorination treatment of aqueous samples reduces, but does not eliminate, the mutagenic effect of the azo dyes Disperse Red 1, Disperse Red 13 and Disperse Orange 1

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Differential Toxicity of Disperse Red 1 and Disperse Red 13 in the Ames Test, HepG2 Cytotoxicity Assay, and Daphnia Acute Toxicity Test

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Analyses of the genotoxic and mutagenic potential of the products formed after the biotransformation of the azo dye Disperse Red 1

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High-Performance Liquid Chromatographic Quantification of Flavonoids in Eriocaulaceae Species and Their Antimicrobial Activity

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Avaliação da atividade mutagênica do extrato etanólico bruto de Paepalanthus latipes (Eriocaulaceae) e dos compostos flavonoídicos 7-metoxilados relacionados

Paepalanthus latipes (Silveira) é uma das plantas brasileiras nativas da Serra do Cipó, Minas Gerais, conhecida como sempre-vivas e muito exportada para os Estados Unidos, Europa e Japão, por seu valor ornamental. Poucos resultados são relatados quanto à atividade biológica destas plantas. Este trabalho teve como objetivo avaliar a atividade mutagênica do extrato etanólico bruto de P. latipes e de dois flavonóides 7-metoxilados dele isolados (7-metilquercetagetina e 7-metilquercetagetina-4'-O-β-D-glicopiranosídeo), através do teste de Ames, utilizando linhagens mutantes de Salmonella typhimurium TA98 e TA100. A atividade mutagênica das amostras testadas, em concentrações variando de 62,5 a 375 μg/placa, foi determinada com ativação metabólica (utilizando-se a fração microssomal S9) e na ausência dessa. Os resultados demonstraram que, tanto o extrato etanólico bruto de P. latipes quanto os flavonóides 7-metoxilados testados, não induziram atividade mutagênica nas linhagens TA98 e TA100.

Mutagenicity of Flavonoids Assayed by Bacterial Reverse Mutation (Ames) Test

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Chemical and Antidiarrheal Studies of Plinia cauliflora

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ANTIMICROBIAL ACTIVITY of CARPOLOBIA LUTEA EXTRACTS and FRACTIONS

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Chemical Constituents of the Methanolic Extract of Leaves of Leiothrix spiralis Ruhland and Their Antimicrobial Activity

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Broiler litter reutilization applying different composting concepts

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Microbiological quality of salmon (Salmo salar) sold in cities of the state of São Paulo, Brazil

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Chemical composition and apparent digestibility of the ostrich offal meal for Nile tilapia

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