CHEMICAL SYNTHESIS OF A NOVEL AROMATIC AMINE MUTAGEN ISOLATED FROM WATER OF THE NISHITAKASE RIVER IN KYOTO AND A POSSIBLE ROUTE OF ITS FORMATION

Among five mutagenic compounds isolated from water samples, taken at s ites below the sewage plants of the Nishitakase River in Kyoto, Japan, the structure of compound I has been determined to be is(2-methoxyeth yl)amino]-5-methoxyphenyl]-5-amino- 7-bromo-4-chloro-2H-benzotriazole (PBTA-1). Since this novel aromatic amine mutagen has characteristic s ubstituents in its molecule, it is postulated that the azo dye, 4-meth oxy-5-[bis(2-methoxyethyl)amino]acetoanilide (AZO DYE-1), used as an i ndustrial material, is converted to the corresponding 2-phenylbenzotri azole derivative with a reducing reagent and subsequently to PBTA-1 by chlorination. In fact, AZO DYE-1 changed to the dechlorinated derivat ive of PBTA-1 (deClPBTA-1) on treatment with sodium hydrosulfite, and this reacted with sodium hypochlorite to produce PBTA-1. Moreover, the presence of deClPBTA-1 was confirmed in a river water sample, along w ith PBTA-1. PBTA-1 showed potent mutagenic activities in Salmonella ty phimurium TA98 and YG1024, inducing 88 000 and 3 000 000 revertants, r espectively, per mu g, with S9 mix, deClPBTA-1 was also mutagenic, but less potent. From these observations, it is suggested that PBTA-1 is produced from AZO DYE-1 through deClPBTA-1, during industrial processe s at dyeing factories and the treatment of wastewater at sewage plants .