Electrochemical characteristics of nitro-heterocyclic compounds of biological interest. III. Nitroso derivative formation.
Upon electrolytic reduction of a range of nitro-aromatic complexes (including imidazoles, benzenoids, furans and pyrazoles) an associated oxidation-reduction process is observed at more positive potentials with respect to nitro group reduction when using repeat scan cyclic voltammetry. This new couple has been identified as the reversible first reduction of the nitroso derivative for chloramphenicol, by the addition of a genuine sample of nitrosochloramphenicol to the electrochemical cell. We have failed to observe formation of the new redox-active species for five 5-nitroimidazoles examined. Possible reaction schemes for nitroso formation under electrolytic reduction conditions and the importance of the nitroso redox couple with respect to the cytotoxic action of the parent drug are discussed. The applicability of nitrosochloramphenicol as a model for the behaviour of nitro-heterocycles in general is shown.
Tocher
J H
JH
Chemotherapy Research Unit, North East London Polytechnic.
Edwards
D I
DI
D002701:Chloramphenicol; D007093:Imidazoles; D008920:Misonidazole; D009603:Nitroso Compounds; D010084:Oxidation-Reduction; D011720:Pyrazoles
D007093:Imidazoles; D009603:Nitroso Compounds; D011720:Pyrazoles; D002701:Chloramphenicol; D008920:Misonidazole