title: Hexofuranosyl thymidines inserted into oligodeoxynucleotides via their two exocyclic hydroxy groups. Oligo synthesis and RNase H activity.
abstract: Hexofuranosyl nucleosides are considered as conformationally restricted acyclic nucleosides using a furanose ring to link the diol backbone to the nucleobase. The phosphoramidite of 1-(2,3-dideoxy-beta-D-erythro-hexofuranosyl)thymine was synthesized from thymidine with formation of a new stereocentre at C-5' and the nucleoside was used in oligodeoxynucleotide (ODN) synthesis. Binding of mixed sequence ODNs towards complementary DNA and RNA showed decreased affinity compared to the wild-type oligos. Insertion in the middle of poly alphaT sequence led to stabilization of ODN/dA(14) duplexes at low ionic strength, but a decrease was observed in medium and high salt buffers compared to d(alphaT)(14)/dA(14). Both beta and alpha hexofuranosyl thymidines allowed cleavage of complementary mixed-sequence RNA by RNase H to the 3'-site of the modification in ODNs whereas a limited inhibition was detected from the 5'-site.
authors.affiliation: Department of Chemistry, Nucleic Acid Center, University of Southern Denmark, DK-5230 Odense M, Denmark.
authors.forename: Vyacheslav V
authors.initials: VV
authors.lastname: Filichev
authors.forename: Birte
authors.initials: B
authors.lastname: Vester
authors.forename: Erik B
authors.initials: EB
authors.lastname: Pedersen
mesh_terms: D001483:Base Sequence; D005663:Furans / Q000737:chemistry* / Q000378:metabolism; D006878:Hydroxides / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis* / Q000302:isolation & purification / Q000378:metabolism*; D016914:Ribonuclease H / Q000378:metabolism*; D013936:Thymidine / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005663:Furans; D006878:Hydroxides; D009838:Oligodeoxyribonucleotides; D016914:Ribonuclease H; D013936:Thymidine