2'-O-PROPARGYL OLIGORIBONUCLEOTIDES - SYNTHESIS AND HYBRIDIZATION

Fully modified oligonucleotide sequences containing 2'-O-propargylribo nucleotides were synthesised on automated DNA-synthesisers using the p hosphoramidite approach. A highly selective alkylation procedure was u sed to introduce the propargyl functionality, thereby enabling the syn thesis of protected 2'-O-propargyl-3'-O-phosphoramidites, building blo cks for the assembly of 2'-O-propargyl oligoribonucleotides. The suita bility of phosphoramidite chemistry for the introduction of this modif ied nucleoside was proven using MALDI or ES mass spectrometry of the f inal oligomer. The 2'-O-propargyl oligoribonucleotides showed an incre ase in the Tm of duplexes with complementary RNA relative to the corre sponding RNA homoduplex. These analogues should prove useful for a var iety of antisense applications. (C) 1998 Elsevier Science Ltd. All rig hts reserved.