title: Synthesis of aminoglycoside conjugates of 2'-O-methyl oligoribonucleotides.
abstract: Aminoglycoside conjugates of 2'- O-methyl oligoribonucleotides have been synthesized entirely on a solid phase using conventional phosphoramidate chemistry. For this purpose, appropriately protected neamine-derived phosphoramidites, viz., 2-cyanoethyl [6,3',4'-tri- O-levulinoyl- N (1), N (3), N (2) (') , N (6) (') -tetra(trifluoroacetyl)neamine-5- O-ethyl] N,N-diisopropylphosphoramidite, 1, and 2-cyanoethyl [6,3',4',2'',3''-penta- O-levulinoyl- N (1), N (3), N (2) (') , N (6) (') -tetra(trifluoroacetyl) ribostamycin-5''-yl] N, N-diisopropylphosphoramidite, 2, have been prepared and attached via phosphodiester linkage to an appropriate 2'- O-methyl oligoribonucleotide. Levulinoyl esters are used to cap the hydroxyl groups of the aminoglycoside moieties, since they may be selectively removed prior to ammonolysis. In this manner, the potential O-->N acyl migration is excluded. Applicability of the strategy has been demonstrated by the synthesis of eight different aminoglycoside conjugates, in which 1 and 2 are attached directly to the 5'-end ( 6 and 10) or, alternatively, to an inserted non-nucleosidic hydroxyalkyl armed branching unit ( 3, 4, or 5), which results in intrachain conjugates ( 7- 9, 11- 13). The potential of these conjugates to act as a sequence-selective artificial nuclease has been studied.
authors.affiliation: Department of Chemistry, University of Turku, FIN-20014 Turku, Finland.
authors.forename: Kaisa
authors.initials: K
authors.lastname: Ketomäki
authors.forename: Pasi
authors.initials: P
authors.lastname: Virta
mesh_terms: D000617:Aminoglycosides / Q000138:chemical synthesis*; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis*; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D007202:Indicators and Reagents; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008670:Metals / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009843:Oligoribonucleotides / Q000138:chemical synthesis*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D007202:Indicators and Reagents; D008670:Metals; D009843:Oligoribonucleotides