Anodic Behaviour of Flavonoids Orientin, Eriodictyol and Robinin at a Glassy Carbon Electrode

Orientin, eriodictyol and robinin are polyphenolic compounds, and their oxidation mechanism is pH‐dependent, in two steps, involving a different number of electrons and protons. Orientin and eriodictyol first oxidation occurs at a lower potential, corresponding to the reversible oxidation of the catechol group, and is followed by an irreversible oxidation on the ring‐A at more positive potential. Robenin oxidation is irreversible, with the formation of electroactive products, and occurs at ring‐A and ring‐B. The electrochemical characterization of their redox behaviour brought useful data about their chemical stability, antioxidant and pro‐oxidant activity, enabling a comprehensive understanding of their redox mechanism.