Mutagenic activity of 2-phenylbenzotriazole derivatives related to a mutagen, PBTA-1, in river water

A mutagen, 2-[2-(acetylamino)-4-[bis(2-methoxyethyl)amino]-5-methoxyphenyl] -5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-1), isolated from water of the Nishitakase River in Kyoto exhibits potent mutagenic activity in Salmo nella typhimurium TA98 with S9 mix and has characteristic moieties, includi ng bromo, chloro, acetylamino, bis(2-methoxyethyl)amino and primary amino g roups on a 2-phenylbenzotriazole skeleton. The mutagenicities of PBTA-1, it s congeners and five related 2-phenylbenzotriazoles were examined in S. typ himurium TA98 with S9 mix in order to elucidate the structure-activity rela tionships. The data obtained suggest that a primary amino group plays an es sential role in the mutagenic activity as do aromatic amines including hete rocyclic amines in cooked foods. The effect of planarity of the 2-phenylben zotriazole ring was significant, and in addition, halogen groups of PBTA-1 influenced the enhancement of the mutagenic activity. (C) 1999 Elsevier Sci ence B.V. All rights reserved.