Postlabelling analysis of DNA adducts formed in human hepatoma cells treated with 3-nitrobenzanthrone

3-Nitrobenzanthrone (NBA) is one of the most mutagenic nitroaromatic compounds that has been found recently in diesel exhaust and airborne particles. A [32P]-postlabelling analysis was carried out to examine the adducts in DNA from human hepatoma HepG2 cells treated with NBA. Two major and two minor adduct spots were obtained in the analysis. The structure of the compound obtained from one of the minor adduct spots was identified to be N-acetyl-3-amino-2-(2'-deoxyguanosin-3', 5'-bisphosphate-8-yl)-benzanthrone, based on identical mobility of the compound with that of synthetic standards in thin-layer chromatography and high performance liquid chromatography. This substance is the identical adduct found in our previous in vitro study. The yet-unidentified major adduct spots may be guanosin- and adenosin-benzanthrone adducts without the N-acetyl group.