Analogues of a Locked Nucleic Acid with Three-Carbon 2‘,4‘-Linkages: Synthesis by Ring-Closing Metathesis and Influence on Nucleic Acid Duplex Stability and Structure
作者:Nanna Albæk,、Michael Petersen、Poul Nielsen
DOI:10.1021/jo061225g
日期:2006.9.1
Two bicyclic 2'-deoxynucleoside analogues containing a saturated and an unsaturated three-carbon 2', 4'-linkage, respectively, have been synthesized using a ring-closing metathesis-based linear strategy starting from uridine. Both analogues have been incorporated into oligodeoxynucleotide sequences and increased the stability of DNA:RNA hybrid duplexes (Delta T-m similar to 2.5-5.0 degrees C per modification) and decreased the stability of dsDNA duplexes (Delta T-m similar to 2.5-1.0 degrees C per modification). CD spectroscopy revealed that the bicyclic nucleosides induced formation of A-type-like duplexes albeit to a lesser degree than found for locked nucleic acid (LNA) monomers. From the CD data and UV melting analysis, we propose that the 2'-oxygen atom of the bicyclic moiety is essential for the formation of stabilized A-type-like dsDNA but not for the formation of a stabilized A-type DNA:RNA hybrid.