Methoxylation and Glycosylation Effect on the Redox Mechanism of Citroflavones

The methoxylation and glycosylation effect on the redox mechanism of citroflavones, isorhoifolin, linarin, diosmetin and diosmin, was investigated. All citroflavones hydroxyl groups can be electrochemically oxidised, and the oxidation at the B-ring occurs at a lower potential than at the A-ring. The electrochemical oxidation is irreversible, pH-dependent, with occurrence of one or two oxidation products, which undergo reversible redox reactions, depending on the number of OH substituents on the molecule. The glycosylation leads to a steric effect and decreasing of the oxidation peak currents whereas the methylation involves the formation of nonelectroactive oxidation products.