Electrochemical oxidation of mitoxantrone at a glassy carbon electrode

Mitoxanaone is an anthracycline used as an antitumour antibiotic for leukae mia and breast cancer treatment, due to its interaction with DNA. However, the molecular mechanism of the antitumour action is not completely understo od. Using a glassy carbon electrode the electrochemical oxidation of mitoxa ntrone was shown to be a complex, pH-dependent, irreversible electrode proc ess involving several metabolites. Comparison of the electrochemical oxidat ion 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 mito xantrone and its oxidation products adsorb strongly on the electrode surfac e, causing severe problems of electrode fouling, reproducible electroanalyt ical determinations could only be done at very low concentrations and in an aqueous buffer supporting electrolyte containing 30% ethanol. The detectio n limit obtained was 10(-7) M. (C) 1999 Elsevier Science B.V, All rights re served.