Catechin oxidation products: Mechanistic aspects and kinetics

Abstract

The oxidation of catechin in the presence of atmospheric oxygen in a methanol/buffer model solution was studied by investigating generated products using LC/MS and spectrophotometry. It was proved that catechin was slowly converted to dimeric species with similar structures and properties. The catechin autoxidation was investigated spectrophotometrically at different pH ranging between 5 and 10. Using the initial linear dependence of the kinetic curves [Dimers] = f(t) the initial reaction rates were estimated for the autoxidation of catechin in methanol/buffered solutions. It was found that the dimer formation is favored at pH 8.