Reduction of lapachones and their reaction with L-cysteine and mercaptoethanol on glassy carbon electrodes.

The electrochemical reduction of beta-lapachone and its 3-sulphonic salt was studied by cyclic, square wave and differential pulse voltammetry in aqueous media using a glassy carbon electrode. These compounds have a wide range of biological activities, including antibacterial, cytotoxic, antifungal, trypanocidal and anticancer action. The reduction of beta-lapachone in the presence of L-cysteine and 2-mercaptoethanol was studied and the results, together with others already published, suggest that the anticancer mechanism of beta-lapachones can be explained via interaction with topoisomerase.