- Boronic acid-based autoligation of nucleic acids: Influence of the nature of the 3′-end ribonucleotidic strand
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The development of synthetic systems displaying dynamic and adaptive characteristics is a formidable challenge with wide applications from biotechnology to therapeutics. Recently, we described a dynamic and programmable nucleic acid-based system relying on the formation of reversible boronate internucleosidic linkages. The DNA- or RNA-templated system comprises a 5′-ended boronic acid probe connecting a 3′-ended ribonucleosidic oligonucleotide partner. To explore the dominant factors that control the reversible linkage, we synthesized a series of 3′-end modified ribonucleotidic strands. Evidence suggests that geometric and steric factors are key features for controlling the equilibria.
- Barbeyron, Renaud,Wengel, Jesper,Vasseur, Jean-Jacques,Smietana, Michael
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- Synthesis of spin-labeled riboswitch RNAs using convertible nucleosides and DNA-catalyzed RNA ligation
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Chemically stable nitroxide radicals that can be monitored by electron paramagnetic resonance (EPR) spectroscopy can provide information on structural and dynamic properties of functional RNA such as riboswitches. The convertible nucleoside approach is used to install 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) and 2,2,5,5-tetramethylpyrrolidin-1-oxyl (proxyl) labels at the exocyclic N4-amino group of cytidine and 2′-O-methylcytidine nucleotides in RNA. To obtain site-specifically labeled long riboswitch RNAs beyond the limit of solid-phase synthesis, we report the ligation of spin-labeled RNA using an in vitro selected deoxyribozyme as catalyst, and demonstrate the synthesis of TEMPO-labeled 53 nt SAM-III and 118 nt SAM-I riboswitch domains (SAM = S-adenosylmethionine).
- Büttner, Lea,Seikowski, Jan,Wawrzyniak, Katarzyna,Ochmann, Anne,H?bartner, Claudia
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p. 6171 - 6180
(2013/10/21)
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- Synthesis and anti-HCV activity of 3′,4′-oxetane nucleosides
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Hepatitis C virus afflicts approximately 180 million people worldwide and currently there are no direct acting antiviral agents available to treat this disease. Our first generation nucleoside HCV inhibitor, RG7128 has already established proof-of-concept
- Chang, Wonsuk,Du, Jinfa,Rachakonda, Suguna,Ross, Bruce S.,Convers-Reignier, Serge,Yau, Wei T.,Pons, Jean-Francois,Murakami, Eisuke,Bao, Haiying,Steuer, Holly Micolochick,Furman, Phillip A.,Otto, Michael J.,Sofia, Michael J.
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scheme or table
p. 4539 - 4543
(2010/11/03)
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- Method of preparation of known and novel 2'-modified nucleosides by intramolecular nucleophilic displacement
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A method for the preparation of 2'-modified nucleosides is provided. The method comprises a novel intramolecular nucleophilic displacement reaction. Included in the invention are novel 2'-modified pyrimidines and purines prepared according to the method of the invention, novel pyrimidines and purines bearing a 2',3' heterocyclic substituent and oligonucleotides containing said 2'-modified pyrimidines and purines. The 2'-modified nucleosides are useful as anti-viral and anti-neoplastic agents.
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- Process for the preparation of 2'-O-alkyl purine phosphoramidites
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2'-O-alkylated guanosine, uridine, cytidine, and 2,6-diaminopurine 3'-O-phosphoramidites are prepared by alkylating nucleoside precursors, adding suitable blocking groups and phosphitylating. Alkylation is effected on 2,6-diamino-9-(β-D-ribofuranosyl)purine followed by deamination to prepare guanosine 2'-O-alkylated 3'-O-phosphormidites. Alkylation is effected on a dialkyl stannylene derivative of uridine to prepare uridine 2'-O-alkylated 3'-O-phosphormidites. Alkylation is effected directly on cytidine to prepare cytidine 2'-O-alkylated 3'-O-phosphormidites. Alkylation is effected directly on 2,6-diaminopurine to prepare 2,6-diaminopurine 2'-O-alkylated 3'-O-phosphormidites.
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- 176. Nucleosides part LXI: A simple procedure for the monomethylation of protected and unprotected ribonucleosides in the 2′-O- and 3′-O-position using diazomethane and the catalyst stannous chloride
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Intensive studies on the diazomethane methylation of the common ribonucleosides uridine, cytidine, adenosine, and guanosine and its derivatives were performed to obtain preferentially the 2′-O-methyl isomers. Methylation of 5′-O-(monomethoxytrityl)-N 2-[2-(4-nitrophenyl)ethoxycarbonyl]-O 6-[2-(4-nitrophenyl)ethyl]-guanosine (1) with diazomethane resulted in an almost quantitative yield of the 2′-nd 3′-O-methyl isomers which could be separated by simple silica-gel flash chromatography (Scheme 1). Adenosine, cytidine, and uridine were methylated with diazomethane with and without protection of the 5′-O-position by a mono- or dimethoxytrityl group and the aglycone moiety of adenosine and cytidine by the 2-(4-nitrophenyl)ethoxycarbonyl (npeoc) group (Schemes 2-4). Attempts to increase the formation of the 2′-O-methyl isomer as much as possible were based upon various solvents, temperatures, catalysts, and concentration of the catalysts during the methylation reaction.
- Cramer, Hagen,Pfleiderer, Wolfgang
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p. 2114 - 2136
(2007/10/03)
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- Oligo(2′-O-methylribonucleotides) and their derivatives. II. Synthesis and properties of oligo(2′-O-methylribonucleotides) modified with N-(2-hydroxyethyl)phenazinium and steroid groups at the 5′-terminus
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Oligo(2′-O-methylribonucleotides) modified at the 5′-terminus with a steroid (cholesterol or testosterone) or polycyclic aromatic dye N-(2-hydroxyethyl)phenazinium residue were synthesized. It was shown that the introduction of an N-(2-hydroxyethyl)phenazinium moiety into octa(2′-O-methylribonucleotide) increased the melting temperature of the duplex with the d-target by 9°C. The steroid residue, which was attached to the 5′-position of deca(2′-O-methyluridylate) via a phosphodiester linkage, enhanced the stability of the steroid conjugate complexes with d(pA)16 and (pA)16; this effect was stronger with the cholesterol derivative (ΔTm 5 and 8°C, respectively) than with the testosterone derivative(ΔTm 1 and 4°C).
- Sergeeva,Lokhov,Ven'yaminova
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p. 800 - 806
(2007/10/03)
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- Simplified synthesis of 2′ -O-alkyl ribopyrimidines
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Direct 2′-hydroxyl alkylation (R = methyl, ethyl, propyl, pentyl or allyl) of 5′-dimethoxytrityl-N-(t-butylphenoxyacetyl or benzoyl)-cytidine 1 was achieved by reaction in the presence of silver I oxide and a catalytic amount of pyridine with excess alkyl
- Hodge, Richard P.
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p. 2933 - 2936
(2007/10/02)
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