- Enzymatic Synthesis of Therapeutic Nucleosides using a Highly Versatile Purine Nucleoside 2’-DeoxyribosylTransferase from Trypanosoma brucei
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The use of enzymes for the synthesis of nucleoside analogues offers several advantages over multistep chemical methods, including chemo-, regio- and stereoselectivity as well as milder reaction conditions. Herein, the production, characterization and utilization of a purine nucleoside 2’-deoxyribosyltransferase (PDT) from Trypanosoma brucei are reported. TbPDT is a dimer which displays not only excellent activity and stability over a broad range of temperatures (50–70 °C), pH (4–7) and ionic strength (0–500 mM NaCl) but also an unusual high stability under alkaline conditions (pH 8–10). TbPDT is shown to be proficient in the biosynthesis of numerous therapeutic nucleosides, including didanosine, vidarabine, cladribine, fludarabine and nelarabine. The structure-guided replacement of Val11 with either Ala or Ser resulted in variants with 2.8-fold greater activity. TbPDT was also covalently immobilized on glutaraldehyde-activated magnetic microspheres. MTbPDT3 was selected as the best derivative (4200 IU/g, activity recovery of 22 %), and could be easily recaptured and recycled for >25 reactions with negligible loss of activity. Finally, MTbPDT3 was successfully employed in the expedient synthesis of several nucleoside analogues. Taken together, our results support the notion that TbPDT has good potential as an industrial biocatalyst for the synthesis of a wide range of therapeutic nucleosides through an efficient and environmentally friendly methodology.
- Pérez, Elena,Sánchez-Murcia, Pedro A.,Jordaan, Justin,Blanco, María Dolores,Manche?o, José Miguel,Gago, Federico,Fernández-Lucas, Jesús
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p. 4406 - 4416
(2018/09/14)
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- NON-NATURAL RIBONUCLEOTIDES, AND METHODS OF USE THEREOF
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One aspect of the present invention relates to modified nucleosides and oligonucleotides comprising such modified nucleosides. Another aspect of the invention relates to a method of inhibiting the expression of a gene in call, the method comprising (a) co
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Page/Page column 111
(2009/10/22)
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- Synthesis and anti-HIV activity of 2-substituted 2'-deoxy-2'- fluoroadenosines
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2-Iodo-6-methoxypurine 2'-deoxy-2'-fluororiboside 8 was prepared from 2- iodo-6-methoxypurine riboside 1 in 8 steps. Reaction of 8 with ammonia in methanol gave the 2-iodoadenosine derivative 9 in 69% yield. Treatment of 9 with various nucleophiles gave 2-substituted analogues of 2'-deoxy-2'- fluoroadenosine 10-12. 2'-Deoxy-2,2'-difluoroadenosine 14 was also prepared by the treatment of the quaternary salt 13 with fluoride ion, but similar reactions of 13 with chloride or bromide ion gave the corresponding piperidine congeners 15a,b.
- Maruyama,Utsumi,Sato,Richman
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p. 1219 - 1230
(2007/10/02)
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- Synthesis and biologic activity of purine 2'-deoxy-2'-fluoro- ribonucleosides
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The synthesis of 3,5-di-O-benzoyl-2-deoxy-2-fluoro-D-ribofuranosyl bromide (8) and its reaction with 2,6-dichloropurine by fusion and with mercuric cyanide catalysis is described. The resulting 2,6-dichloro-9-(3,5-di-O- benzoyl-2-deoxy-2-fluoro-β-D-ribofuranosyl)purine (13) was converted to the 2-fluoroadenine (16), the 2-chloroadenine (17), 2,6-diaminopurine (12), and guanine (14) nucleosides by standard procedures. These nucleosides were cytotoxic to a number of cell lines in culture. The 2-haloadenine nucleosides 16 and 17 gave modest increases in lifespan when tested against the P388 leukemia in mice.
- Thomas,Tiwari,Clayton,Secrist III,Montgomery
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p. 309 - 323
(2007/10/02)
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- Purine 2'-deoxy-2'-fluororibosides as antiinfluenza virus agents
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Twenty purine 2'-deoxy-2'-fluororibosides were synthesized by enzymic pentosyl transfer from 2'-deoxy-2'-fluorouridine. Each nucleoside analogue was assayed for cytotoxicity in uninfected Madin-Darby canine kidney cells and for their ability to suppress influenza A virus infections in these cells. The most potent antivirial activity was observed with analogues having an amino group in the 2-position of the purine moiety. All 2-unsubstituted analogues were less potent than their 2-amino counterparts. Furthermore, 2- methyl, 2-methoxy, or 2-fluoro substitution obliterated antivirial activity. The most cytotoxic member of the series was the 2-fluoro-6-amino analogue (IC50 = 120 μM). 2'-Deoxy-2'-fluoroguanosine and those congeners readily converted to it by adenosine deaminase showed the most potent antivirial activity (IC50 = 15-23 μM). Little cytotoxicity was observed with this subgroup of analogues which renders them worthy of further investigation as potential antiinfluenza agents.
- Tuttle,Tisdale,Krenitsky
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p. 119 - 125
(2007/10/02)
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