Mestrado em Ciências Farmacêuticas (FF)
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Navegando Mestrado em Ciências Farmacêuticas (FF) por Por Orientador "GIL, Eric de Souza"
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Item Caracterização eletroquímica e estudos mecânico-quânticos para obtenção de propriedades eletrônicas de parabenos(Universidade Federal de Goiás, 2011-02-28) BARBOSA, Núsia Luísa; GIL, Eric de Souza; http://lattes.cnpq.br/3218622824233303Parabens are antimicrobial preservatives widely used in the pharmaceutical, cosmetic and food industries. The alkyl side chain connected to the ester group defines some important physicochemical characteristics of these compounds, including the partitioning coefficient and redox properties. The voltammetry and computational analysis were carried out in order to evaluate the redox behavior of these compounds and other phenolic analogues. Correlations between chemical substituents inductive effects of parabens with potential shifts were observed. Using cyclic voltammetry and glassy carbon working electrode, in aqueous, only one single irreversible anodic peak was observed around 0.8 V for methylparaben (MP), etylparaben (EP), propylparaben (PP), butylparaben (BP), benzylparaben (BzP) and phenolic analogues. The positive inductive effect of alkyl groups was demonstrated by the anodic oxidation potential shift to lower values as the carbon number increases and, therefore the parabens (and other phenolic analogues) oxidation processes to the quinoninic forms showed great dependence of substituent pattern. It was further evaluated the influence of pH and composition of supporting electrolyte in voltammetric profile of parabens.Item Cromatografia em camada delgada acoplada a voltametrias cíclica e de pulso diferencial na análise de ácido rosmarínico de Rosmarinus officinalis Linné (Alecrim)(Universidade Federal de Goiás, 2010-12-06) GONÇALVES, Darlene; CONCEIÇÃO, Edemilson Cardoso da; http://lattes.cnpq.br/7193007113950510; GIL, Eric de Souza; http://lattes.cnpq.br/3218622824233303This study shows a solid-state electroanalytical method for identification and quantification of rosmarinic acid (RA), a phytoantioxidant of great interest for its therapeutical advantages and applicability in food, cosmetics and pharmaceuticals areas; after it had been isolated from Rosmarinus officinalis Linné (rosemary) samples through thin layer chromatography (TLC), then the silica containing the isolated analyte (chromatographic stain) scraped from chromatographic plates was used to prepare carbon paste electrodes, which were subjected to analysis by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The proposed method showed excellent analytical potential, low cost, speed, ease of implementation and linearity, which can also be applied to other phytoantioxidants in quality control practices of herbal drugs, contributing to the evaluation and quality assurance of them.