Metronidazole is the most important drug of the group of 5-nitroimidazoles and possesses toxicity to anaerobic micro-organisms DNA being the main target for their biological action. The mechanism of biological action of metronidazole is dependent upon the nitro group reduction process. The reduction of metronidazole is pH dependent in acid medium and four electrons are involved in the complete reduction to the hydroxylamine derivative. In aprotic medium the reduction of the metronidazole occurs in two steps, the first involving one electron to form the nitro radical and the second step involving three more electrons until the formation of the hydroxylamine derivative. In this paper the mechanism of reduction of metronidazole was studied by using the voltammetric techniques: d.c. polarography, differential pulse polarography and cyclic voltammetry using the mercury drop as the working electrode.
metronidazole; nitro radical; voltammetry; polarography
