Chrisman, W., Tanga, M. J., & Knize, M. G. (2008). Synthesis and mutagenic potency of structural isomers of 2‐amino‐1‐methyl‐6‐phenylimidazo [4, 5‐b] pyridine. Journal of Heterocyclic Chemistry, 45(6), 1641-1649.
Synthesis of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), three structural isomers, and two desphenyl PhIP congeners has been carried out. Mutagenic potency was evaluated using S. typhimurium strain TA98 in the Ames test. Mutagenic potency increased in relation to structural features in these heterocyclic amines that allow extended resonance between the phenyl and imidazo[4,5-b]pyridine N2-amino substituents. By contrast, PhIP isomers, whose substitution disallows involvement of the phenyl group in their aminoimidazo resonance hybrids, and desphenyl congeners were from 86- to 234-fold less mutagenic than PhIP.