title: Selective phosphate protection: a novel synthesis of double-labeled oligonucleotides.
abstract: [structure: see text] A novel, selective labeling of oligonucleotides with two different reporter groups is described. The oligonucleotide is synthesized using a stable 2-(4-methoxybenzamido)ethyl protection for a selected internucleosidic thiophosphate (PS) and a labile 2-(N-isopropyl-4-methoxybenzamido)ethyl for the 3'-terminal PS and internucleosidic phosphates. The latter group and the base protection are removed, and the 3'-terminal PS is labeled. The former protection is then cleaved by a prolonged ammonolysis, and the second reporter is introduced at the internucleosidic PS.
authors.affiliation: Department of Medicinal Chemistry, Isis Pharmaceuticals, 2292 Faraday Avenue, Carlsbad, California 92008, USA. aguzaev@isisph.com
authors.forename: A P
authors.initials: AP
authors.lastname: Guzaev
authors.forename: M
authors.initials: M
authors.lastname: Manoharan
mesh_terms: D005456:Fluorescent Dyes / Q000737:chemistry*; D009841:Oligonucleotides / Q000138:chemical synthesis*; D009943:Organophosphorus Compounds / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D009841:Oligonucleotides; D009943:Organophosphorus Compounds