title: Simple solid-phase synthesis and biological properties of carbohydrate-oligonucleotide conjugates modified at the 3'-terminus.
abstract: A novel synthesis method for oligonucleotides possessing a functional moiety at the 3'-terminus was established based on solid-phase synthesis. In order to install the functional group at the 3'-terminus of the oligonucleotide, a solid support possessing the functional group was prepared. A carbohydrate was employed in this study for the functionalization of the oligonucleotide. To prepare a glycosylated solid support, a novel glycosyl acceptor (2) was synthesized using 4,4-dihydroxymethyl-cyclopenta-1-ene as the starting compound. The glycosylation reaction proceeded smoothly (yield = 95%) to yield the suitable glycosylated compound (3). After 8 was immobilized on the solid support, it was subjected to solid-phase oligonucleotide synthesis by the standard phosphoramidite coupling method. An oligonucleotide possessing a sugar moiety at the 3'-terminus was obtained after the products were deprotected and cleaved from the solid support. The stability of the carbohydrate-modified oligonucleotide was greatly increased even in the serum buffer, indicating that the sugar moiety at the 3'-position improved the resistance against enzymatic degradation. This technique was also applied to RNA synthesis. Galactose-ended siRNA was prepared and was confirmed to possess enough ability, at a concentration of 10 nM, to regulate the expression of the target gene.
authors: Grauate School of Pure and Applied Science, Tsukuba Research Center for Interdisciplinary Materials Science, University of Tsukuba, CREST, Japan Science and Technology Agency.
authors: Yutaka
authors: Y
authors: Ikeda
authors: Daisuke
authors: D
authors: Kubota
authors: Yukio
authors: Y
authors: Nagasaki
mesh_terms: D001483:Base Sequence; D002241:Carbohydrates / Q000138:chemical synthesis* / Q000737:chemistry; D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D005690:Galactose / Q000737:chemistry; D009841:Oligonucleotides / Q000138:chemical synthesis* / Q000737:chemistry; D009943:Organophosphorus Compounds / Q000737:chemistry; D012313:RNA / Q000138:chemical synthesis / Q000737:chemistry; D034741:RNA, Small Interfering / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D002241:Carbohydrates; D009841:Oligonucleotides; D009943:Organophosphorus Compounds; D034741:RNA, Small Interfering; C434331:phosphoramidite; D012313:RNA; D005690:Galactose