Potent methyl oxidation of 5-methyl-2′-deoxycytidine by halogenated quinoid carcinogens and hydrogen peroxide via a metal-independent mechanism

► Three methyl oxidation products were generated in a mixture of 5mdC, TCBQ, and H2O2. ► The oxidation was markedly inhibited by
- OH scavengers and under anaerobic conditions. ► Analogous effects were observed in the classic Fenton system. ► The proposed mechanism may partly explain the carcinogenicity of halogenated quinones.