Abstract
Electrochemical oxidation of eupafolin was investigated in a 0.1 M phosphate buffer solution by different electrochemical techniques and different pH values. Cyclic voltammetry, chronoamperometry, rotating disc electrode voltammetry, as well as controlled potential bulk electrolysis were used in this work. Eupafolin presents a reversible oxidation peak followed by reduction peak after changing the direction of the potential sweep. The current peaks are pH- dependent. The heterogeneouscharge transfer rate constants at different eupafolin concentration and diffusion coefficient of the eupafolin in buffer solution were determined. Bulk electrolysis of the eupafolin in the phosphate buffer solution yields a single oxidation product, o-quinone. The proposed scheme of eupafolin transformation under the condition of anodic-cathodic polarization involves o-quinone formation due to two-electron transfer followed by eupafolin formation from o-quinone after changing the direction of the potential sweep.