title: 2'-modified-2-thiothymidine oligonucleotides.
abstract: [reaction: see text] Oligonucleotides with novel modifications, 2'-O-[2-(methoxy)ethyl]-2-thiothymidine and 2'-deoxy-2'-fluoro-2-thiothymidine, have been synthesized. These modified oligonucleotides exhibited very high thermal stability when hybridized with complementary RNA. 2-O-(2-Methoxy)ethyl-2-thiothymidine modified oligonucleotide phosphodiesters showed enhanced resistance toward nucleases (t(1/2) > 24 h), but 2'-deoxy-2'-fluoro-2-thiothymidine modified oligonucleotide phosphodiesters showed limited stability to nucleotytic degradation.
authors.affiliation: Department of Medicinal Chemistry, Isis Pharmaceuticals, Inc., Carlsbad, California 92008, USA.
authors.forename: Kallanthottathil G
authors.initials: KG
authors.lastname: Rajeev
authors.forename: Thazha P
authors.initials: TP
authors.lastname: Prakash
authors.forename: Muthiah
authors.initials: M
authors.lastname: Manoharan
mesh_terms: D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000737:chemistry; D004355:Drug Stability; D006358:Hot Temperature; D009841:Oligonucleotides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D018075:RNA, Complementary / Q000737:chemistry; D012910:Snake Venoms; D013936:Thymidine / Q000031:analogs & derivatives*
chemical_list: D018076:DNA, Complementary; D009841:Oligonucleotides; D018075:RNA, Complementary; D012910:Snake Venoms; D010727:Phosphoric Diester Hydrolases; D013936:Thymidine