- Enzymatic synthesis of 2-deoxy-β-d-ribonucleosides of 8-azapurines and 8-aza-7-deazapurines
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The enzymatic synthesis of 8-azapurine and 8-aza-7-deazapurine 2-deoxyribonucleosides has been studied. Two methods have been used: (i) transglycosylation employing 2-deoxyguanosine, 2-deoxycytidine, 2-deoxyuridine, and 2-deoxythymidine as 2-deoxy-d-ribofuranose donors and recombinant E. coli purine nucleoside phosphorylase (PNP) as biocatalyst, and (ii) one-pot synthesis from 2-deoxy-d-ribose and nucleobases employing recombinant E. coli ribokinase (RK), phosphopentomutase (PPM) and PNP as biocatalysts. Good substrate activity was observed for all bases studied except 2-amino-8-aza-6-chloro-7-deazapurine, which afforded the desired N9-nucleoside in moderate yield due to very low solubility of the base and partial replacement of C6-chloro atom of the base and formed nucleoside with a hydroxy group. The participation of Ser90 Oγ of E. coli PNP in the binding of 8-aza-7-deazapurines in the catalytic center of PNP followed by the formation of a productive complex and glycosidic bond is suggested. Georg Thieme Verlag Stuttgart · New York.
- Stepchenko, Vladimir A.,Seela, Frank,Esipov, Roman S.,Miroshnikov, Anatoly I.,Sokolov, Yuri A.,Mikhailopulo, Igor A.
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experimental part
p. 1541 - 1545
(2012/09/08)
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- Enhancement of nucleoside cytotoxicity through nucleotide prodrugs
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A common reason for the lack of cytotoxicity of certain nucleosides is thought to be their inability to be initially activated to the monophosphate level by a nucleoside kinase or other activating enzyme. In a search for other nucleosides that might be wo
- Rose, Jerry D.,Parker, William B.,Someya, Hitoshi,Shaddix, Sue C.,Montgomery, John A.,Secrist III, John A.
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p. 4505 - 4512
(2007/10/03)
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- Process for selectively producing 1-phosphorylated sugar derivative anomer and process for producing nucleoside
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A desired isomer is selectively prepared by phosphorolyzing and isomerizing an anomer mixture of a 1-phosphorylated saccharide derivative while crystallizing one of the isomers to displace the equilibrium. Furthermore, using the action of a nucleoside phosphorylase, a nucleoside is prepared from the 1-phosphorylated saccharide derivative obtained and a base with improved stereoselectivity and a higher yield. This process is an anomer-selective process for preparing a 1-phosphorylated saccharide derivative and a nucleoside.
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- SYNTHESIS OF 2-DEOXY-β-D-RIBONUCLEOSIDES AND2,3-DIDEOXY.β-D-PENTOFURANOSIDES ON IMMOBILIZED BACTERIAL CELLS
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Alginate gel-entrapped cells of auxotrophic thymine-dependent strain of E. coli catalyze the transfer of 2-deoxy-D-ribofuranosyl moiety of 2'-deoxyuridine to purine and pyrimidine bases as well as their aza and deaza analogs.All experiments invariably gave β-anomers; in most cases, the reaction was regiospecific, affording N9-isomers in the purine and N1-isomers in the pyrimidine series.Also a 2,3-dideoxynucleoside can serve as donor of the glycosyl moiety.The acceptor activity of purine bases depends only little on substitution, the only condition being the presence of N7-nitrogen atom.On the other hand, in the pyrimidine series the activity is limited to only a narrow choice of mostly short 5-alkyl and 5-halogeno uracil derivatives.Heterocyclic bases containing amino groups are deaminated; this can be avoided by conversion of the base to the corresponding N-dimethylaminomethylene derivative which is then ammonolyzed.The method was verified by isolation of 9-(2-deoxy-β-D-ribofuranosyl) derivatives of adenine, guanine, 2-chloroadenine, 6-methylpurine, 8-azaadenine, 8-azaguanine, 1-deazaadenine, 3-deazaadenine, 1-(2-deoxy-β-D-ribofuranosyl) derivatives of 5-ethyluracil, 5-fluorouracil, and 9-(2,3-deoxy-β-D-pentofuranosyl)hypoxanthine, 9-(2,3-deoxy-β-D-pentofuranosyl)-6-methylpurine, and other nucleosides.
- Votruba, Ivan,Holy, Antonin,Dvorakova, Hana,Guenter, Jaroslav,Hockova, Dana,et al.
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p. 2303 - 2330
(2007/10/02)
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