Abstract
Determination was made of the mutagenicity and DNA breaking activity of nitrososesamol derivedfrom nitrosation of sesamol in sesame oil. Nitrososesamol was found to be mutagenic toward the Salmonella typhimurium TA100 strain without metabolic activation. This compound induced DNA single strand breaks when incubated with supercoiled plasmid DNA at pH 7.4 and 37 °C. Breaking occurreddue to active oxygen species generated from nitrososesamol and dissolved oxygen since it was inhibitedin the absence of oxygen and in the presence of scavengers of active oxygen species. Hydroxyl radicalwas detected in a solution of nitrososesamol by electron spin resonance (ESR) -spin trapping. The DNAstrand breaking activity of nitrososesamol was enhanced by cysteine. The breaking activity of a mixtureof nitrososesamol and cysteine was found due to active oxygen species since breaking was suppressed inthe absence of oxygen and in the presence of scavengers of active oxygen species. A phenoxyl radicaland complex radical species wei4 generated in a mixture of nitrososesamol and cysteine, but neither ofthese may contribute to breaking. Other nitrosophenols also induced DNA strand breaking in the absence and presence of cysteine via active oxygen species.
