An electrochemical method for the determination of the anticancer platinum drug carboplatin using a DNA-modified electrode was developed. This electrode was successfully used for the electrochemical determination of carboplatin in serum samples of patients with ovarian cancer undergoing treatment. The electrochemical results clearly demonstrated that, for low concentrations, carboplatin interacts preferentially with adenine rather than guanine groups in the DNA and they can contribute to clarifying the mechanisms of interaction of platinum anticancer drugs with DNA. The pharmacokinetics c o r m ondIng to the administration of the drug was followed electrochemically and the detection limit in serum samples was 5.7 x 10 M. Due to a similar mechanism of reaction with DNA other platinum anticancer drugs can be determined by this method.
The surface of an electrochemical glassy carbon electrode was modified with a layer of double-stranded DNA (dsDNA) or with double-stranded DNA conditioned in single-stranded DNA (ssDNA) and was used to investigate mitoxantrone-DNA interactions. Differential pulse and square wave voltammetry were applied to develop an electroanalytical procedure for the determination of mitoxantrone and evaluate its interaction with dsDNA or ssDNA immobilized on the electrode surface. The results demonstrate that MTX interaction with DNA is not specific to either guanine or adenine bases. The kinetics of the mitoxantrone-DNA interaction is slow and damage to DNA was followed with time.
Mitoxantrone is an anthracycline used as an antitumour antibiotic for leukaemia and breast cancer treatment, due to its interaction with DNA. However, the molecular mechanism of the antitumour action is not completely understood. Using a glassy carbon electrode the electrochemical oxidation of mitoxantrone was shown to be a complex, pH-dependent, irreversible electrode process involving several metabolites. Comparison of the electrochemical oxidation behaviour of mitoxantrone, ametantrone and aminantrone enabled a deeper understanding of the mechanism and showed the relevance of electrochemical data for the understanding of the cytotoxicity of mitoxantrone. Since mitoxantrone and its oxidation products adsorb strongly on the electrode surface, causing severe problems of electrode fouling, reproducible electroanalytical determinations could only be done at very low concentrations and in an aqueous buffer supporting electrolyte containing 30% ethanol. The detection limit obtained was 10 À7 M. #
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.