title: Disulfide-linked oligonucleotide phosphorothioates:  novel analogues of nucleic acids.
abstract: The synthesis of phosphorothioate analogues of oligonucleotides by the oxidation of deoxyadenosine 3',5'-bisphosphorothioate (3) was attempted.  Cyclization of 3 is much more efficient than oligomerization under all the conditions investigated.  However, a preformed oligonucleotide carrying a 5'-terminal phosphorothioate group undergoes efficient chain-extension when oxidized in the presence of 3.
authors.affiliation: The Salk Institute for Biological Studies, San Diego, CA 92186-5800, USA.
authors.forename: T
authors.initials: T
authors.lastname: Wu
authors.forename: L E
authors.initials: LE
authors.lastname: Orgel
mesh_terms: D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000138:chemical synthesis; D003839:Deoxyadenosines; D004220:Disulfides / Q000032:analysis*; D004791:Enzyme Inhibitors / Q000138:chemical synthesis; D009696:Nucleic Acids / Q000032:analysis*; D009841:Oligonucleotides / Q000032:analysis* / Q000737:chemistry*; D010084:Oxidation-Reduction; D011108:Polymers; D013698:Templates, Genetic; D013873:Thionucleotides / Q000138:chemical synthesis
chemical_list: D003839:Deoxyadenosines; D004220:Disulfides; D004791:Enzyme Inhibitors; D009696:Nucleic Acids; D009841:Oligonucleotides; D011108:Polymers; D013873:Thionucleotides; C016957:adenosine-3',5'-cyclic phosphorothioate; D000242:Cyclic AMP