Identification of the DNA adduct formed by metabolism of 1,8-dinitropyrene in Salmonella typhimurium

The incubation of [³H]1,8-dinitropyrene with Salmonella typhimuriumTA98NR followed by isolation of the DNA from these cells, hydrolysisof the DNA to nucleosides, butanol extraction of the hydrolysateand purification by reversed-phase liquid chromatography affordeda single product. Calf thymus DNA, after treatment with N-hydroxyl-1-amino-8-nitropyrene,was hydrolyzed, extracted and purified in a similar fashionto give a single compound which was shown to be the deoxyguanosinederivative 1-N-(2'-deoxyguanosin-8-yl)-amino-8-nitropyrene bya combination of proton n.m.r. and u.v.-vis. spectroscopy andfast atom bombardment mass spectrometry. The DNA adducts formedin vivo and in vitro exhibited identical chromatographic andchemical behavior. Under acidic or basic conditions the in vivoand in vitro adducts were converted to identical products. Reductionof the adduct gave a new, highly fluorescent product that hada fluorescent emission spectrum identical to that of 1,8-diaminopyrene.