Superoxide Anion Radical Interaction With New Quinoline Compounds Measured By Cyclic Voltammetry

Abstract

Cyclic voltammetry was used to study the interaction of four quinoline∙ −derivatives with superoxide anion radical (O 2 ). This method is basedon the decrease of the anodic peak current of the superoxide anionradical O∙ 2 − generated electrochemically by the reduction of molecularoxygen O2 dissolved in acetonitrile. The results obtained reveal that allderivatives showed a higher antioxidant activity than the standard usedBHT. The binding parameters of the studied compounds wereestimated in terms of binding constant (kb ), ratio of Binding Constants(K Red ⁄K Ox ) and binding Gibbs free energy (ΔG°). From the results, itappears that the binding constant kb of the tested compounds is veryhigh ranged from 15922 to 26181 L.mol-1 while negative values of ΔG°indicate the spontaneity of the antiradical reaction. It was also foundthat interaction of the reduced form O∙ 2 − with all derivatives is strongerthan the oxidized form O2 with ratio of binding constants values in therange 1.21-159.