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

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. U ovom radu ispitivan je, u uslovima in vitro, preko elektronskih apsorpcionih spektara, strukturni transformacioni tok malvina u acetatnim vodenim puferskim rastvorima sirokog opsega pH vrednosti. Pored spektrohemijskog ispitivano je i voltametrijsko ponasanje kao i mehanizam redoks procesa ovog molekula u cilju definisanja njegovih antioksidativnih osobina. Preko elektronskih apsorpcionih spektara konstatovano je da promene u strukturi malvina, koje su uslovljene pH vrednostima sredine, uslovljavaju i razlicito voltametrijsko ponasanje ovog molekula. Razlicita zavisnost oksidacionog potencijala malvina od pH koja se moze objasniti prisustvom razlicitih struktura molekula malvina, elektrohemijski aktivnih na razlicitim pH vrednostima, ukazuje na promenu mehanizma elektrodnog procesa. Voltametrijska aktivnost malvina semikvantitativno je uporedjena sa voltametrijskom aktivnoscu standardnog sintetskog antioksidansa, BHA, i prirodnog antioksidansa, kvercetina.