C8-N-arylamine adducts of 2'-deoxyguanosine (2'-dG) play an important role in the induction of the chemical carcinogenesis caused by aromatic amines. C8-N-acetyl-N-arylamine dG adducts that differ in their substitution pattern in the aniline moiety were converted by cycloSal technology into the corresponding C8-N-acetyl-N-arylamine-2'-deoxyguanosine-5'-triphosphates and C8-NH-arylamine-2'-deoxyguanosine-5'-triphosphates. Their conformation preference has been investigated by NOE spectroscopy and DFT calculations. The substrate properties of the C8-dG adducts were studied in primer-extension assays by using Klenow fragment exo(-) of Escherichia coli DNA polymerase I and human DNA polymerase β. It was shown that the incorporation was independent of the substitution pattern in the aryl moiety and the N-acetyl group. Although the triphosphates were poor substrates for the human polymerases, they were incorporated twice before the termination of the elongation process occurred; this might demonstrate the importance of C8-N-arylamine-2'-deoxyguanosine-5'-triphosphates in chemical carcinogenesis.

An efficient procedure was developed to prepare homo-Cnucleosides. The β-allyl C-glycoside of D-ribose was transformed into the thienopyrimidine nucleoside and the benzodiazepine nucleoside of 2-deoxy-D-ribose. For incorporation into oligonucleotides by solid-phase synthesis, both derivatives were transformed into the related 3Ј-phosphoramidite building blocks. These phosphoramidites were then sitespecifically incorporated into DNA oligonucleotides. The modified DNA strands were hybridized with different DNA

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