Synthesis and Characterization of an RNA Dinucleotide Containing a 3‘-S-Phosphorothiolate Linkage
摘要:
The synthesis of an RNA dinucleotide (IspU) containing a 3'-S-phosphorothiolate linkage is described. The compound is prepared from 9-(3-deoxy-3-iodo-beta-D-xylofuranosyl)hyperanthine with installation of the phosphorothiolate group via an Arbusov reaction and protection of the ribose 2'-hydroxyl as a silyl ether. IspU is found to be a substrate for several enzymes including T4 polynucleotide kinase, snake venom phosphodiesterase, and ribonuclease T-2. Base-catalyzed cleavage of the dinucleotide is accelerated (similar to 2000-fold) relative to that of the phosphate-linked compound IpU. Product characterization and kinetic analysis show that IspU is cleaved through the same mechanism as IpU. The observed rate acceleration is argued to reflect stabilization of the anionic transition state by the polarizable sulfur atom.
Nucleic Acid-Related Compounds. 88. Efficient Conversions of Ribonucleosides into Their 2',3'-Anhydro, 2'(and 3')-Deoxy, 2',3'-Didehydro-2',3'-dideoxy, and 2',3'-Dideoxynucleoside Analogs
摘要:
Treatment of purine, pyrimidine, and modified purine (antibiotic) ribonucleosides with 2-acetoxy-2-methylpropanoyl (alpha-acetoxyisobutyryl) bromide in acetonitrile gave mixtures of 2',3'-bromohydrin acetates with different O5' substituents. Significant amounts of 5'-unprotected (hydroxyl) bromo acetates were obtained in some cases, and formation of 2',3'-O-isopropylidene derivatives as minor byproducts was detected for the first time. Acid-catalyzed nucleophilic displacement of chloride by bromide occurred with 2-amino-6-chloropurine riboside, but no substitution of fluoride by bromide was detected with 6-amino-2-fluoropurine riboside. Treatment of the trans bromo acetate mixtures obtained from purine-type nucleosides with Dowex 1 x 2 (OH-) in methanol gave the 2',3'-anhydro (ribo epoxide) compounds. Radical-mediated hydrogenolytic debromination and deprotection gave 2'- and 3'-deoxynucleosides. Treatment of the bromo acetate mixtures with zinc-copper couple or acetic acid-activated zinc effected reductive elimination, and deprotection gave 2',3'-didehydro-2',3'-dideoxy compounds which were hydrogenated to give 2',3'-dideoxynucleosides. A number of these analogues have potent inhibitory activity against AIDS and hepatitis B viruses. New C-13 NMR data for several types of unsaturated-sugar nucleosides are tabulated. These procedures are directly applicable for the preparation of L-didehydro-dideoxy and L-dideoxy nucleoside analogues.
Nucleic Acid-Related Compounds. 88. Efficient Conversions of Ribonucleosides into Their 2',3'-Anhydro, 2'(and 3')-Deoxy, 2',3'-Didehydro-2',3'-dideoxy, and 2',3'-Dideoxynucleoside Analogs
作者:Morris J. Robins、John S. Wilson、Danuta Madej、Nicholas H. Low、Fritz Hansske、Stanislaw F. Wnuk
DOI:10.1021/jo00129a034
日期:1995.12
Treatment of purine, pyrimidine, and modified purine (antibiotic) ribonucleosides with 2-acetoxy-2-methylpropanoyl (alpha-acetoxyisobutyryl) bromide in acetonitrile gave mixtures of 2',3'-bromohydrin acetates with different O5' substituents. Significant amounts of 5'-unprotected (hydroxyl) bromo acetates were obtained in some cases, and formation of 2',3'-O-isopropylidene derivatives as minor byproducts was detected for the first time. Acid-catalyzed nucleophilic displacement of chloride by bromide occurred with 2-amino-6-chloropurine riboside, but no substitution of fluoride by bromide was detected with 6-amino-2-fluoropurine riboside. Treatment of the trans bromo acetate mixtures obtained from purine-type nucleosides with Dowex 1 x 2 (OH-) in methanol gave the 2',3'-anhydro (ribo epoxide) compounds. Radical-mediated hydrogenolytic debromination and deprotection gave 2'- and 3'-deoxynucleosides. Treatment of the bromo acetate mixtures with zinc-copper couple or acetic acid-activated zinc effected reductive elimination, and deprotection gave 2',3'-didehydro-2',3'-dideoxy compounds which were hydrogenated to give 2',3'-dideoxynucleosides. A number of these analogues have potent inhibitory activity against AIDS and hepatitis B viruses. New C-13 NMR data for several types of unsaturated-sugar nucleosides are tabulated. These procedures are directly applicable for the preparation of L-didehydro-dideoxy and L-dideoxy nucleoside analogues.
Synthesis and Characterization of an RNA Dinucleotide Containing a 3‘-<i>S</i>-Phosphorothiolate Linkage
作者:Lara B. Weinstein、David J. Earnshaw、Richard Cosstick、Thomas R. Cech
DOI:10.1021/ja9616903
日期:1996.1.1
The synthesis of an RNA dinucleotide (IspU) containing a 3'-S-phosphorothiolate linkage is described. The compound is prepared from 9-(3-deoxy-3-iodo-beta-D-xylofuranosyl)hyperanthine with installation of the phosphorothiolate group via an Arbusov reaction and protection of the ribose 2'-hydroxyl as a silyl ether. IspU is found to be a substrate for several enzymes including T4 polynucleotide kinase, snake venom phosphodiesterase, and ribonuclease T-2. Base-catalyzed cleavage of the dinucleotide is accelerated (similar to 2000-fold) relative to that of the phosphate-linked compound IpU. Product characterization and kinetic analysis show that IspU is cleaved through the same mechanism as IpU. The observed rate acceleration is argued to reflect stabilization of the anionic transition state by the polarizable sulfur atom.