Polarographic analysis of heterocyclic nitrogen compounds

• Published in: Journal of electroanalytical chemistry and interfacial electrochemistry 1981-01, Vol.129 (1), p.213-227
• Main Authors: Leach, Steven C., Weaver, Robert D., Kinoshita, Kimio, Lee, William W.
• Format: Article
• Language: English
• ISSN: 0022-0728
• DOI: 10.1016/S0022-0728(81)80015-0

A correlation between the reduction potential of heterocyclic compounds and their effectiveness as radiosensitizing agents in cancer therapy has been reported in the literature. This correlation provides a guide for evaluating the effectiveness of newly synthesized compounds as radiosensitizers. The half-wave reduction potential ( E 1/2) of selected nitroimidazoles, nitrotriazoles and heterocyclic amine N-oxides was measured at a dropping mercury electrode in a Britton-Robinson buffer, pH 7.4. The effect of various substituent groups on the half-wave reduction potential of the heterocyclic compounds was investigated and the results are compared with published data. A single reduction wave was observed with the nitroimidiazoles and nitrotriazoles, whereas multiple reduction waves were conserved with several of the N-oxides of pyridine, quinoxaline and phenazine. When electron-attracting substituents were attached to the heterocyclic ring on nitroimidazole and nitrotriazole, the reduction of the nitro group was easier and E 1/2 shifted in the positive direction relative to that of the parent compound.