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

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 mechanism showed that it is a complex multistep electron transfer with deprotonation steps involved and that the final products, dimers o r polymers, adsorb strongly to the electrode, forming an unreactive 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.

Oxidation of Sanguinarine and Its Dihydro‐Derivative at a Pyrolytic Graphite Electrode Using Ex Situ Voltammetry. Study of the Interactions of the Alkaloids with DNA

“…Reduction processes of QBAs can also be partially studied using carbon electrodes as was shown in studies focused on the redox behavior of SG, CHE and fagaronine at glassy carbon and pyrolytic graphite electrodes (GCE and PGE) 29. Oxidation of the isoquinoline alkaloids (QBAs, protoberberines and protopine) 30–33, vinca alkaloids (vinblastine, its semisynthetic derivatives vindesine, 5′‐noranhydrovinblastine, and vincristine) 34, 35, ergot alkaloids 36, colchicine 37–39, and mammalian alkaloid β‐carboline 40, 41 has been described in detail using DPV and SWV at GCE, PGE and other carbon‐type electrodes. The methods above can be used for analysis of trace (nanogram) amounts of the alkaloids, e.g.…”

Portable solid-state sensor for therapeutic monitoring of an antineoplastic drug; vinblastine in human plasma

“…13,14 Different methods have been reported in the literature for the determination of vinblastine including spectrophotometry, 15,16 thin layer chromatography, 17 high-performance liquid chromatography, [18][19][20][21][22][23][24][25][26] capillary electrophoresis, [27][28][29][30][31] and voltammetric methods. [32][33][34][35][36][37] As far as the authors' knowledge, no potentiometric sensor is reported in the literature for the determination of vinblastine. Therefore, it was our concern to develop a simple, sensitive, and selective method for the quantitative analysis of such a life-saving drug, taking advantage of the superior inherent benets of ion-selective electrode-potentiometry such as simplicity, portability, rapidity, and lower energy consumption.…”

Voltammetry of Vinblastine Sulfate in Acetonitrile

“…The mechanistic pathway was proposed in order to elucidate the possible routes for these drugs within biological system. 8 The mechanism for the coupling of the compound which belongs to the same family as that of catharanthus roseus was studied in detail. Special emphasis was laid on the orientation of the chemical bonds and the interaction between steric and electronic effects of the reactants and products.…”