Caracterização eletroquímica e estudos mecânico-quânticos para obtenção de propriedades eletrônicas de parabenos
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2011-02-28
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Universidade Federal de Goiás
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Parabens 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.
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BARBOSA, Núsia Luísa. Electrochemical characterization and quantum-mechanical studies to obtain the eletronic properties of parabens. 2011. 71 f. Dissertação (Mestrado em Ciências da Saúde - Farmácia) - Universidade Federal de Goiás, Goiânia, 2011.