Anodic behavior of some Vinca alkaloids with cytostatic activity: Effect of pH

✍ Scribed by A. M. Oliveira Brett; M. M. M. Grazina; T. R. A. Macedo; D. Raimundo

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 345 KB
• Volume: 6
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/elan.1140060111

✦ Synopsis

Abstract

The anodic oxidation mechanism of the Vinca alkaloids vinblastine, its semisynthetic derivatives vindesine and 5′‐noranhydrovinblastine, and of vincristine, all with closely similar structures, was studied at a glassy carbon disk electrode in buffered aqueous media using differential pulse and cyclic voltammetry. The effect of pH on the mecharism showed that it is a complex multistep electron transfer with deprotonation steps involved and that the final products, dimers or polymers, adsorb strongly to the electrode, forming an unreactve film on the electrode surface. The electrochemical differential pulse voltammograms showed a correlation between the vinblastine derivatives, whereas vincristine reacts at different potentials. These differences in the anodic oxidation mechanisms of the compounds studied can be related to their neurotoxicity and myelosuppression effects. These effects may be due to the metabolite and/or degradation products of the compounds and result from how they are attached to, or transported across, cellular structures such as cell membranes.