Electrochemical oxidation mechanism of procarbazine at glassy carbon electrode

• The electrochemistry of procarbazine at a glassy carbon electrode was studied.
• Procarbazine at glassy carbon electrode exhibits four well defined anodic peaks.
• Procarbazine is oxidizable at glassy carbon electrode under a pH-dependent process.
• An electrochemical oxidation mechanism for procarbazine is outlined.

A voltammetric study of the redox behavior of procarbazine (PCZ), one of the most used chemotherapy agents to face Hodgkin’s lymphoma, was carried out to investigate its oxidation at glassy carbon electrode (GCE). Essays of cyclic, differential pulse and square-wave voltammetries, on a large pH interval, revealed the electrochemical oxidation behavior of PCZ as an irreversible adsorption-controlled oxidation process, occurring in four consecutive charge transfer steps. The first, second and third steps are pH-dependent and occur with the transfer of one electron and one proton, leading to the formation of an electroactive product in acid media, while the last one is pH-independent, involving the transfer of one electron. A reaction mechanism for the electrochemical oxidation of PCZ is proposed, where, in the first and second step the oxidation occurs on the hydrazine group, followed by isomerization and, after hydrolysis, conversion to benzaldehyde-procarbazine. The third and fourth steps are associated with the oxidation of the benzaldehyde-procarbazine with the production of the N-isopropylterephthalic acid.