The identification and characterization of a urinary mutagen resulting from cigarette smoke

The urine of a cigarette smoker who excretes exceptionally mutagenic urine was analyzed for several factors affecting mutagenicity. S. typhimurium strain TA98 was always more sensitive to XAD-2 urine concentrates than TA100. With TA98, as high as 85 revertants per ml of urine were produced. It was observed that incubation with beta-glucuronidase was not required for expression of mutagenicity but that a complete S9 mix was needed to convert the material in the concentrate to the ultimate mutagenic species. TLC and HPLC separation of the XAD-2 urine concentrate resulted in the identification of trace amounts of the bladder carcinogen, 2-aminonaphthalene (beta-naphthylamine) and a considerable amount of a possible metabolite of 2-aminonaphthalene, 2-amino-7-naphthol. The identity of the compounds was confirmed by mass spectral analysis, and 2-amino-7-naphthol was shown to be a mutagen for TA100 and TA98 when activated by rat-liver S9.