- The anomers of 8-aza-7-deaza-2′-deoxy-adenosine
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The structures of 4-amino-1-(2-deoxy-β-D-erythro-pentofuranosyl)-1H-pyrazolo[3,4-d] pyrimidine, (I), and 4-amino-1-(2-deoxy-α-D-erythro-pentofuranosyl)-1H-pyrazolo[3,4-d] pyrimidine, (II), both C10H13N5O3, have been determined. The sugar puckering of both compounds is C-2′-endo-C-3′exo (2′T3′) (S-type sugar). The N-glycosidic torsion angle χ1 is in me anti range [-106.3 (2)° for (I) and 111.5 (3)° for (II)] and the crystal structure is stabilized by hydrogen bonds.
- Seela, Frank,Zulauf, Matthias,Reuter, Hans,Kastner, Guido
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- Revisiting Pyrazolo[3,4- d]pyrimidine Nucleosides as Anti- Trypanosoma cruzi and Antileishmanial Agents
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Chagas disease and visceral leishmaniasis are two neglected tropical diseases responsible for numerous deaths around the world. For both, current treatments are largely inadequate, resulting in a continued need for new drug discovery. As both kinetoplastid parasites are incapable of de novo purine synthesis, they depend on purine salvage pathways that allow them to acquire and process purines from the host to meet their demands. Purine nucleoside analogues therefore constitute a logical source of potential antiparasitic agents. Earlier optimization efforts of the natural product tubercidin (7-deazaadenosine) involving modifications to the nucleobase 7-position and the ribofuranose 3′-position led to analogues with potent anti-Trypanosoma brucei and anti-Trypanosoma cruzi activities. In this work, we report the design and synthesis of pyrazolo[3,4-d]pyrimidine nucleosides with 3′- and 7-modifications and assess their potential as anti-Trypanosoma cruzi and antileishmanial agents. One compound was selected for in vivo evaluation in an acute Chagas disease mouse model.
- Bouton, Jakob,Ferreira De Almeida Fiuza, Ludmila,Cardoso Santos, Camila,Mazzarella, Maria Angela,De Nazaré Correia Soeiro, Maria,Maes, Louis,Karalic, Izet,Caljon, Guy,Van Calenbergh, Serge
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p. 4206 - 4238
(2021/05/04)
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- 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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- 8-Aza-7-deazaadenine and 7-deazaguanine: Synthesis and properties of nucleosides and oligonucleotides with nucleobases linked at position-8
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The 8-aza-7-deazaadenine (pyrazolo[3,4-d]pyrimidin-4-amine) N8-(2′-deoxyribonucleoside) (2) and the 7-deazaguanine (pyrrolo[3,4-d]pyrimidine-2-amin-(3H)-4-one) C8-(2′-deoxyribonucleoside) (4) were synthesized and incorporated in olig
- Seela,Debelak
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p. 577 - 585
(2007/10/03)
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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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- Synthesis and Hydrolytic Stability of 4-Substituted Pyrazolopyrimidine 2'-Deoxyribofuranosides
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Phase-transfer glycosylation of 4-chloro-1H-pyrazolopyrimidine (1) with 2-deoxy-3,5-di-O-(p-toluoyl)-α-D-erythro-pentofuranosyl chloride (2) yielded the N-1 glycosylation product (3) in 42 percent.The protected intermediate (3) was converted into pyrazolopyrimidine 2'-deoxyribofuranosides with amino, oxo, and thioxo substituents at C-4.Kinetic data of proton-catalysed hydrolysis showed that pyrazolopyrimidine 2'-deoxyribofuranosides are more stable at the N-glycosylic bond than are the parent purine nucleosides.
- Seela, Frank,Steker, Herbert
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p. 2573 - 2576
(2007/10/02)
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- Synthesis of 2'-Deoxytubercidin, 2'-Deoxyadenosine, and Related 2'-Deoxynucleosides via a Novel Direct Stereospecific Sodium Salt Glycosylation Procedure
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A general and stereospecific synthesis has been developed for the direct preparation of 2'-deoxy-β-D-ribofuranosylpurine analogues including 2'-deoxyadenosine derivatives.The reaction of the sodium salt of 4-chloropyrrolopyrimidine (4) or 2,4-dichloropyrrolopyrimidine (1) with 1-chloro-2-deoxy-3,5-di-O-p-toluoyl-α-D-erythro-pentofuranose (25) provided the corresponding N-1,2'-deoxy-β-D-ribofuranosyl blocked derivatives (5 and 2) which, on ammonolysis, gave 2'-deoxytubercidin (6) and 2-chloro-2'-deoxytubercidin (3), respectively, in good yield.This glycosylation also readily proceeds in the presence of a 2-methylthio group.Application of this glycosylation procedure to 4,6-dichloroimidazopyridine (10), 6-chloropurine (16), 2,6-dichloropurine (13), and 4-chloropyrazolopyrimidine (19) gave 2-chloro-2'-deoxy-3-deazaadenosine (12), 2-'-deoxyadenosine (18), 2-chloro-2'-deoxyadenosine (15), and 4-amino-1-(2-deoxy-β-D-erythro-pentofuranosyl)pyrazolopyrimidine (21), respectively.Similarly, glycosylation and ammonolysis of 4,6-dichloro-1H-pyrrolopyridine (22) gave 4,6-dichloro-1-(2-deoxy-β-D-erythro-pentofuranosyl)pyrrolopyridine (24).This stereospecific attachment of the 2-deoxy-β-D-ribofuranosyl moiety appears to be due to a Walden inversion at the C-1 carbon of 25.
- Kazimierczuk, Zygmunt,Cottam, Howard B.,Revankar, Ganapathi R.,Robins, Roland K.
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p. 6379 - 6382
(2007/10/02)
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