Redox behavior of the ellagitannin oenothein B and ellagic acid at a glassy carbon electrode

Abstract

Oenothein B and ellagic acid are polyphenolic compounds, and their oxidation mechanism is pH- dependent, in one step, involving a different number of electrons and protons. Oenothein B and ellagic acid first oxidation occurs at a lower potential, corresponding to the quasi-reversible oxidation of the phenolic hydroxyl groups. The oxidation of both compounds leads to the formation of electroactive products that undergoes an irreversible oxidation process at higher potentials. The electrochemical characterization of their redox behavior brought useful data about their chemical stability, antioxidant and pro-oxidant activity, enabling a comprehensive understanding of their redox mechanism.