Structural Identification of DNA Adducts Derived from 3-Nitrobenzanthrone, a Potent Carcinogen Present in the Atmosphere

3‐Nitrobenzanthrone is a powerful bacterial mutagen and carcinogen to mammals. To obtain precise information on DNA‐adduct formation by 3‐nitrobenzanthrone, a number of DNA adducts, including N‐(2′‐deoxyguanosin‐8‐yl)‐3‐aminobenzanthrone (13 a), 2‐(2′‐deoxyguanosin‐N2‐yl)‐3‐aminobenzanthrone (14 a), N‐(2′‐deoxyadenosin‐8‐yl)‐3‐aminobenzanthrone (15 a), 2‐(2′‐deoxyadenosin‐N6‐yl)‐3‐aminobenzanthrone (16 a), and their N‐acetylated counterparts 13 b, 14 b, 15 b, and 16 b were synthesized by palladium‐catalyzed aryl amination of the corresponding nucleoside and bromobenzanthrone derivatives. Among these DNA adducts, DNA adducts 13 a, 13 b, 14 a, 14 b, and 16 a were identified in the reaction mixture of nucleosides (2′‐deoxyguanosine, 2′‐deoxyadenosine, or DNA) with N‐acetoxy‐3‐aminobenzanthrone or N‐acetyl‐N‐acetoxy‐3‐aminobenzanthrone, both of which are recognized as activated metabolites of 3‐nitrobenzanthrone. The formation of these multiple DNA adducts may help explain the potent mutacarcinogenicity of 3‐nitrobenzanthrone. The Tropic of Cancer: 3‐Nitrobenzanthrone (1) is a powerful carcinogen present in the atmosphere. With palladium‐catalyzed aryl amination as a key step, several DNA adducts, the formation of which is recognized as a trigger of chemical carcinogenesis, can be synthesized. Some of these adducts are formed from the reaction of DNA with metabolic activation products of 1. dA=2′‐deoxyadenosine, dG=2′‐deoxyguanosine, R=H, Ac.