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The spectroabsorptiometric and voltammetric behavior of malvin in buffered solutions and its antioxidant properties

Ignjatović Ljubiša M. (Faculty of Physical Chemistry, Belgrade, Yugoslavia)
Dimitrić-Marković Jasmina M. (Faculty of Physical Chemistry, Belgrade, Yugoslavia)
Marković Dragan A. (Faculty of Physical Chemistry, Belgrade, Yugoslavia)
Baranac Jelisaveta M. (Faculty of Physical Chemistry, Belgrade, Yugoslavia)

In the present work the structural transformations of malvin in aqueous acetate buffer solutions were investigated over a wide pH range under in vitro conditions using electronic absorption spectroscopy. In addition to the spectroabsorptiometric investigation, the voltammetric behavior and the mechanism of the redox process of this molecule were studied, in order to define its antioxidant properties. The electronic absorption spectra reveal that the structural changes of malvin, caused by changes in the pH of the medium, lead to changes in the voltammetric behaviour of this molecule. The dependence of the oxidation potential of malvin on pH, which can be explained by the presence of different electroactive molecular structures of malvin at different pH values, indicates different mechanisms of the electrode process. The voltammetric activity of malvin is compared semiquantitatively with the voltammetric activity of a standard synthetic antioxidant, BHA, and a natural antioxidant, quercetin.

Keywords: malvin, UV-VIS spectra, cyclic voltammetry, antioxidant properties.