Nitrosatable Precursors of Mutagens in Foods
This chapter discusses the occurrence of nitrosatable compounds such as indole and phenol derivatives in foods and drugs and the structures and biological properties of their nitrosated products. Several research groups looked for the presence of nitrosatable mutagen precursors in foods, to produce direct-acting mutagens by reaction with nitrite. Incubation of fava beans in nitrite-containing acidic solutions resulted in the formation of direct-acting mutagens as detected with the Salmonella/microsome assay. The presence of the mutagens was demonstrated by isolating the mutagenic fractions through blue-rayon adsorption, a method used to extract polycyclic compounds, and subsequent high-performance liquid chromatography. The DNAs of the forestomach and glandular stomach gave six common spots on two-dimensional chromatography, three of which were also produced by in vitro reaction of this compound with DNA. Direct-acting nitrosoindole compounds forms DNA adducts and also induce ornithine decarboxylase activity in the rat stomach.