Abstract
SAFEER A., FARIA S. (2012). Antioxidant activity coefficient, mechanism, and kinetics of different derivatives of flavones and flavanones towards superoxide radical. Czech J. Food Sci., 30: 153-163.
A systematic investigation of the electrochemically generated superoxide radical (O-2(center dot-)) has been conducted in the presence of some flavonoids, Cyclic voltammetry was used to generate O-2(center dot-) by reducing the molecular oxygen in DMSO at room temperature. The scavenging of the radical was monitored by the decrease in anodic or/and cathodic currents while linearly increasing the concentration of the flavonoid. The strength of interaction was quantified in terms of the binding constant (K-b) values ranging from 1 x 10(2) and 5 x 10(3)M(-1). The antioxidant activity coefficient (K-ao) was calculated from the linear part of the plot of 'current decrease vs. flavonoid concentration: Radical scavenging mechanism of the antioxidant was proposed and discussed in terms of the structure activity relationship. Nicholson-Shain method was employed to estimate the bimolecular homogeneous kinetics and on this basis control use of antioxidant is pointed out.