Synthesis and properties of 2'-O-alkylated 2-thiouridine derivatives and oligonucleotides containing 2'-O-alkylated 2-thiouridine derivatives.

Oligonucleotides containing 2-thiouridine form stable RNA duplexes with complementary RNAs and show high selectivity in the base pair recognition. Moreover, alkylation of the 2'-hydroxyl group provides new insight into developments of new antisense RNAs capable of formation of more stable duplexes with target RNAs. Oligonucleotides having such properties are desirable as agents for the antisense strategy and SNPs analysis. In this study, we report a new method for the synthesis of 2-thiouridine and its 2'-O-alkylated derivatives. The hybridization and structural properties of these modified nucleosides were also studied in detail by the 1H NMR analysis and melting temperature (Tm) measurement of RNA duplexes.