Synthesis and hybridization affinity of oligodeoxyribonucleotides incorporating 4-N-(N-arylcarbamoyl)deoxycytidine derivatives

Modified oligodeoxynucleotides incorporating 4-N-(N-arylcarbamoyl)-dC derivatives 1a–c were synthesized. The 1H NMR spectra of 1a–c suggest that the carbamoyl group forms an intramolecular hydrogen bond with the cytosine ring nitrogen atom so that formation of a Watson–Crick base pair with the complementary guanine base is inhibited. The hybridization properties of oligodeoxynucleotides containing 1a–c were investigated by use of Tm analysis. The hybridization properties of 4-N-(N-phenylcarbamoyl)-dC (1a) were similar to those of 4-N-(N-alkylcarbamoyl)-dC derivatives reported previously. In sharp contrast to 1a, it turned out that 4-N-(N-napht-1-yl) and (N-quionol-5-yl)-dC (1b,c) have a unique property as a universal base.