N2-guanyl and N6-adenyl arylation of chicken erythrocyte DNA by the ultimate carcinogen of 4-nitroquinoline 1-oxide.

Great quantities of chicken erythrocyte DNA with high levels of modification were obtained in vitro by reaction with 4-acetoxyaminoquinoline 1-oxide, a model ultimate carcinogen of 4-nitroquinoline 1-oxide. After enzymatic hydrolysis of the modified DNA, the three main adducts were separated and isolated by semipreparative high performance liquid chromatography. These three adducts were already characterized in vivo and in vitro in our previous work (S. Galiègue-Zouitina et al., Cancer Res., 45: 520-525, 1985). The structure of one of them was previously identified as N-(deoxyguanosin-8-yl)-4-aminoquinoline 1-oxide (B. Bailleul et al., Cancer Res., 41: 4559-4565, 1981). In this paper we have identified by mass spectroscopy and nuclear magnetic resonance the structures of the two other main adducts as 3-(deoxyguanosin-N2-yl)-4-aminoquinoline 1-oxide and 3-(deoxyadenosin-N6-yl)-4-aminoquinoline 1-oxide, respectively.