Hybridization properties and enzymatic recognitions of naphthyridine:imidazopyridopyrimidine base pairs

We describe the synthesis of 1,8-naphthyridine C-nucleosides, Na-N(O) and Na-O(N), and full details of hybridization properties of the duplexes containing naphthyridine:imidazopyridopyrimidine pairs. The desired compounds were obtained from Na-O(N) derivative 1 via conversions of the substituents of 2- and 7-positions, respectively. The 17mer duplex containing one Na-O(O):Im-N(N) pair in the center was stabilized by +11.4 degrees C relative to that containing a T:A pair, and this value was highest among the naphthyridine:imidazopyridopyrimidine pairs.