Isolation and characterization of oligodeoxynucleotides containing dG-N2-AAF and oxidation products of dG-C8-AF

Decadeoxynucleotides containing N-(deoxyguanosine-N2-yl)-2-acetylaminofluorene (dG-N2-AAF) and three recently described products of oxidation of N-(deoxyguanosine-8-yl)-2-aminofluorene (dG-C8-AF) were isolated and characterized. dG-N2-AAF was synthesized; its structure was established by mass spectroscopic and 1H-NMR analysis. Decadeoxynucleotides containing dG-N2-AAF and dG-C8-AAF were prepared by permitting d(CACTAGTCAC) to react with N-acetoxy-AAF and separating the products by HPLC. The decamer containing dG-C8-AAF was incubated under aerobic alkaline conditions. In the presence of 2-mercaptoethanol, the adduct is deacetylated; in the absence of antioxidant, decamers bearing oxidation products are formed. Homogeneity of the modified oligomers was established by polyacrylamide gel electrophoresis. The modified oligodeoxy-nucleotides will be used to introduce dG-N2-aminofluorene adducts and oxidative lesions, site-specifically, into DNA, thereby to correlate these adducts with their mutagenic properties.