118-00-3Relevant articles and documents
Simple method for fast deprotection of nucleosides by triethylamine- catalyzed methanolysis of acetates in aqueous medium
Meier, Lidiane,Monteiro, Gustavo C.,Baldissera, Rodrigo A.M.,Sa?, Marcus Mandolesi
, p. 859 - 866 (2010)
A straightforward methodology for deacetylation of protected ribonucleosides was developed based on triethylamine-catalyzed solvolysis in aqueous methanol. Reactions are completed in a few minutes under microwave irradiation and the free nucleosides are obtained in high yield after simple evaporation of volatiles. Other important features include the involvement of readily available reagents and the compatibility with diverse functional groups, which make this process very attractive for broad application.
N,N-Dibenzyl formamidine as a new protective group for primary amines
Vincent, Stephane,Mons, Stephane,Lebeau, Luc,Mioskowski, Charles
, p. 7527 - 7530 (1997)
Primary amines can be converted in high yield into N,N-dibenzyl formamidines under mild conditions. The N,N-dibenzyl formamidine group was found to be effective as a protective group for primary amines as it is stable to a variety of conditions and can be removed by catalytic hydrogenation.
THE PROTECTION OF 2'-HYDROXY FUNCTIONS IN OLIGORIBONUCLEOTIDE SYNTHESIS
Norman, G. David,Reese, B. Colin,Serafinowska, T. Halina
, p. 3015 - 3018 (1984)
The suitability of the 4-methoxytetrahydropyran-4-yl group for the protection of 2' ( or 3')-hydroxy functions in oligoribonucleotide synthesis is confirmed; the latter protecting group is removed in 0.01M-hydrochloric acid at room temperature under conditions which, contrary to a recent report, lead to no detectable cleavage or migration of the internucleotide phosphodiester linkages.
Chemical radiation studies of 8-bromoguanosine in aqueous solutions
Ioele, Marcella,Bazzanini, Rita,Chatgilialoglu, Chryssostomos,Mulazzani, Quinto G.
, p. 1900 - 1907 (2000)
Chemical radiolytic methods were used to investigate the reactions of hydrated electrons (eaq-) with 8-bromoguanosine (8-Br-Guo) as a function of pH. γ-Radiolysis of 8-Br-Guo in aqueous solutions followed by product studies showed the formation of guanosine (Guo) as a single product at various pH. In D2O solutions the quantitative incorporation of deuterium at the 8-position was also observed. Pulse radiolysis revealed the instantaneous formation of a guanosine radical cation (Guo.+ or its deprotonated forms) in acid or basic solutions. The same transient species results from the reaction of H. with 8-Br-Guo at pH 3, as well as from the reaction of (CH3)2CO.- with 8-Br-Guo at pH 13. In neutral solution, the initial electron adduct was rapidly protonated to give the first observable transient species that decays by first-order kinetics (k = 5 × 104 s-1) to produce the Guo(-H+). radical once again. Tailored experiments allowed the reaction mechanism to be defined in some detail.
Hydrolytic reactions of guanosyl-(3′,3′)-uridine and guanosyl-(3′,3′)-(2′,5′-di-O-methyluridine)
Kiviniemi, Anu,Loennberg, Tuomas,Ora, Mikko
, p. 11040 - 11045 (2004)
Hydrolytic reactions of guanosyl-(3′,3′)-uridine and guanosyl-(3′,3′)-(2′,5′-di-O-methyluridine) have been followed by RP HPLC over a wide pH range at 363.2 K in order to elucidate the role of the 2′-hydroxyl group as a hydrogen-bond donor upon departure of the 3′-uridine moiety. Under neutral and basic conditions, guanosyl-(3′,3′)-uridine undergoes hydroxide ion-catalyzed cleavage (first order in [OH-]) of the P-O3′ bonds, giving uridine and guanosine 2′,3′-cyclic monophosphates, which are subsequently hydrolyzed to a mixture of 2′- and 3′-monophosphates. This bond rupture is 23 times as fast as the corresponding cleavage of the P-O3′ bond of guanosyl-(3′,3′)-(2,5′-di-O-methyluridine) to yield 2′,5′-O-dimethyluridine and guanosine 2′,3′-cyclic phosphate. Under acidic conditions, where the reactivity differences are smaller, depurination and isomerization compete with the cleavage. The effect of Zn2+ on the cleavage of the P-O3′ bonds of guanosyl-(3′,3′)-uridine is modest: about 6-fold acceleration was observed at [Zn2+] = 5 mmol L-1 and pH 5.6. With guanosyl-(3′,3′)-(2′,5′-di-O-methyluridine) the rate-acceleration effect is greater: a 37-fold acceleration was observed. The mechanisms of the partial reactions, in particular the effects of the 2′-hydroxyl group on the departure of the 3′-linked nucleoside, are discussed.
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Uchida,Makino
, p. 1 (1953)
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1,1,1,3,3,3-Hexafluoro-2-propanol for the Removal of the 4,4'-Dimethoxytrityl Protecting Group from the 5'-Hydroxyl of Acid-Sensitive Nucleosides and Nucleotides
Leonard, Nelson J.,Neelima
, p. 7833 - 7836 (1995)
1,1,1,3,3,3-Hexafluoro-2-propanol is introduced as a suitable reagent and solvent for the detritylation of 5'-O-(4,4'-dimethoxytrityl)-nucleosides and -deoxy- nucleosides, especially those that are susceptible to N-glycosyl cleavage under more strongly acidic conditions.
Synthesis of 2'-O-methoxyethylguanosine using a novel silicon-based protecting group.
Wen,Chow, Suetying,Sanghvi, Yogesh S,Theodorakis, Emmanuel A
, p. 7887 - 7889 (2002)
A short and efficient synthesis of 2'-O-methoxyethylguanosine (8) is described. Central to this strategy is the development of a novel silicon-based protecting group (MDPSCl(2), 2) used to protect the 3',5'-hydroxyl groups of the ribose. Silylation of guanosine with 2 proceeded with excellent regioselectivity and in 79% yield. Alkylation of the 2'-hydroxyl group of 6 proceeded with methoxyethyl bromide and NaHMDS and afforded compound 7 in 85% yield, without any noticeable cleavage of the silyl protecting group and without the need to protect the guanine base moiety. Finally, deprotection of 7 was achieved using TBAF and produced 8 in 97% yield.
An efficient approach for conversion of 5-substituted 2-thiouridines built in RNA oligomers into corresponding desulfured 4-pyrimidinone products
Chwialkowska, Anna,Wielgus, Ewelina,Leszczynska, Grazyna,Sobczak, Milena,Mikolajczyk, Barbara,Sochacka, Elzbieta,Nawrot, Barbara
, p. 3100 - 3104 (2015)
Abstract An efficient approach for the desulfuration of C5-substituted 2-thiouridines (R5S2U) bound in the RNA chain exclusively to 4-pyrimidinone nucleoside (R5H2U)-containing RNA products is proposed. This post-synthetic transformation avoids the preparation of a suitably protected H2U phosphoramidite, which otherwise would be necessary for solid-phase synthesis of the modified RNA. Optimization of the desulfuration, which included reaction stoichiometry, time and temperature, allowed to transform a set of ten R5S2U-RNAs into their R5H2U-RNA congeners in ca. 90% yield.
Watson-Crick Base Pairing between Guanosine and Cytidine Studied by 13C Nuclear Magnetic Resonance Spectroscopy
Petersen, Steffen B.,Led, Jens J.
, p. 5308 - 5313 (1981)
Watson-Crick base pairing in dimethyl sulfoxide/methanol (2/1 v/v) between the nucleosides guanosine and cytidine has been studied by carbon -13 nuclear magnetic resonance (13C NMR) spectroscopy at 67.89 MHz.The equilibrium constant for the base pairing complex has been obtained at two different temperatures by a nonlinear least-squares analysis of the experimental shift data for the base carbons, and the enthalpy of interaction has been found to be ca. -3.8 kcal/mol.The analysis furthermore indicates that while base pairing and changes in the syn/anti conformation ratio are independent processes in the case of guanosine, a change from syn to anti conformation occurs simultaneously with the base pairing in the case of cytidine, in agreement with the Watson-Crick base pairing model.As inferred from the results base pairing alters the polarizabilities of the nucleosides.
Biocatalytic separation of N -7/ N -9 guanine nucleosides
Singh, Sunil K.,Sharma, Vivek K.,Olsen, Carl E.,Wengel, Jesper,Parmar, Virinder S.,Prasad, Ashok K.
, p. 7932 - 7935 (2010)
Vorbrueggen coupling of trimethylsilylated 2-N-isobutanoylguanine with peracetylated pentofuranose derivatives generally gives inseparable N-7/N-9 glycosyl mixtures. We have shown that the two isomers can be separated biocatalytically by Novozyme-435-mediated selective deacetylation of the 5′-O-acetyl group of peracetylated N-9 guanine nucleosides.
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Zemlicka,Chladek
, p. 715 (1969)
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Dissociation of Platinum(II) Nucleobase Complexes - Evidence for a Three-path Mechanism via a Five-coordinate Intermediate
Mikola, Marjaana,Vihanto, Jouko,Arpalahti, Jorma
, p. 1759 - 1760 (1995)
In thiourea assisted dissociation of 2+ (Guo = guanosine, dien = diethylenetriamine) in aqueous solution (pH = ca. 3) the nucleophile dependent reaction follows a three-path mechanism, in which the initial binding of the nucleophile to the complex and the ring-opening step of the terdentate dien ligand are reversible.
STRUCTURE OF A NEW MODIFIED NUCLEOSIDE FORMED BY GUANOSINE-MALONALDEHYDE REACTION
Seto, Hiroshi,Akiyama, Kazuyuki,Okuda, Taisuke,Hashimoto, Tsuyoshi,Takesue, Tomoyuki,Ikemura, Tadashi
, p. 707 - 708 (1981)
A new modified nucleoside was formed by the reaction of guanosine with malonaldehyde under acidic condition.This compound emitted strong yellow fluorescence and was hydrolyzed by NaOH into guanosine and malonaldehyde.Its structure was determined to be 1,N2-(1-propenyl-3-ylidene)guanosine by the spectroscopic analysis.
Kinetic properties of Cellulomonas sp. purine nucleoside phosphorylase with typical and non-typical substrates: Implications for the reaction mechanism
Wielgus-Kutrowska, Beata,Bzowska, Agnieszka
, p. 471 - 476 (2005)
Phosphorolysis catalyzed by Cellulomonas sp. PNP with typical nucleoside substrate, inosine (Ino), and non-typical 7-methylguanosine (m7Guo), with either nucleoside or phosphate (Pi) as the varied substrate, kinetics of the reverse synthetic reaction with guanine (Gua) and ribose-1-phosphate (R1P) as the varied substrates, and product inhibition patterns of synthetic and phosphorolytic reaction pathways were studied by steady-state kinetic methods. It is concluded that, like for mammalian trimeric PNP, complex kinetic characteristics observed for Cellulomonas enzyme results from simultaneous occurrence of three phenomena. These are sequential but random, not ordered binding of substrates, tight binding of me substrate purine bases, leading to the circumstances that for such substrates (products) rapid-equilibrium assumptions do not hold, and a dual role of Pi, a substrate, and also a reaction modifier that helps to release a tightly bound purine base. Copyright Taylor & Francis, Inc.
How easily oxidizable is DNA? One-electron reduction potentials of adenosine and guanosine radicals in aqueous solution
Steenken,Jovanovic
, p. 617 - 618 (1997)
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Thermodynamic Reaction Control of Nucleoside Phosphorolysis
Kaspar, Felix,Giessmann, Robert T.,Neubauer, Peter,Wagner, Anke,Gimpel, Matthias
supporting information, p. 867 - 876 (2020/01/24)
Nucleoside analogs represent a class of important drugs for cancer and antiviral treatments. Nucleoside phosphorylases (NPases) catalyze the phosphorolysis of nucleosides and are widely employed for the synthesis of pentose-1-phosphates and nucleoside analogs, which are difficult to access via conventional synthetic methods. However, for the vast majority of nucleosides, it has been observed that either no or incomplete conversion of the starting materials is achieved in NPase-catalyzed reactions. For some substrates, it has been shown that these reactions are reversible equilibrium reactions that adhere to the law of mass action. In this contribution, we broadly demonstrate that nucleoside phosphorolysis is a thermodynamically controlled endothermic reaction that proceeds to a reaction equilibrium dictated by the substrate-specific equilibrium constant of phosphorolysis, irrespective of the type or amount of NPase used, as shown by several examples. Furthermore, we explored the temperature-dependency of nucleoside phosphorolysis equilibrium states and provide the apparent transformed reaction enthalpy and apparent transformed reaction entropy for 24 nucleosides, confirming that these conversions are thermodynamically controlled endothermic reactions. This data allows calculation of the Gibbs free energy and, consequently, the equilibrium constant of phosphorolysis at any given reaction temperature. Overall, our investigations revealed that pyrimidine nucleosides are generally more susceptible to phosphorolysis than purine nucleosides. The data disclosed in this work allow the accurate prediction of phosphorolysis or transglycosylation yields for a range of pyrimidine and purine nucleosides and thus serve to empower further research in the field of nucleoside biocatalysis. (Figure presented.).
