2133-80-4Relevant articles and documents
Enzymatic synthesis of highly fluorescent 8-azapurine ribosides using a purine nucleoside phosphorylase reverse reaction: Variable ribosylation sites
Stachelska-Wierzchowska, Alicja,Wierzchowski, Jacek,Wielgus-Kutrowska, Beata,Mikleusevic, Goran
, p. 12587 - 12598 (2013)
Various forms of purine-nucleoside phosphorylase (PNP) were used as catalysts of enzymatic ribosylation of selected fluorescent 8-azapurines. It was found that the recombinant calf PNP catalyzes ribosylation of 2,6-diamino-8-azapurine in a phosphate-free medium, with ribose-1-phosphate as ribose donor, but the ribosylation site is predominantly N7 and N8, with the proportion of N8/N7 ribosylated products markedly dependent on the reaction conditions. Both products are fluorescent. Application of the E. coli PNP gave a mixture of N8 and N9-substituted ribosides. Fluorescence of the ribosylated 2,6-diamino-8-azapurine has been briefly characterized. The highest quantum yield, ~0.9, was obtained for N9-β-D-riboside (λmax 365 nm), while for N8-β-D-riboside, emitting at ~430 nm, the fluorescence quantum yield was found to be close to 0.4. Ribosylation of 8-azaguanine with calf PNP as a catalyst goes exclusively to N9. By contrast, the E. coli PNP ribosylates 8-azaGua predominantly at N9, with minor, but highly fluorescent products ribosylated at N8/N7.
Aeromonas hydrophila strains as biocatalysts for transglycosylation
Nbile, Matas,Terreni, Marco,Lewkowicz, Elizabeth,Iribarren, Adolfo M.
experimental part, p. 395 - 402 (2011/10/08)
Microbial transglycosylation is useful as a green alternative in the preparation of purine nucleosides and analogues, especially for those that display pharmacological activities. In a search for new transglycosylation biocatalysts, two Aeromonas hydrophila strains were selected. The substrate specificity of both micro-organisms was studied and, as a result, several nucleoside analogues have been prepared. Among them, ribavirin, a broad spectrum antiviral, and the well-known anti HIV didanosine, were prepared, in 77 and 62% yield using A. hydrophila CECT 4226 and A. hydrophila CECT 4221, respectively. In order to scale-up the processes, the reaction conditions, product purification and biocatalyst preparation were analyzed and optimized.
Spectroscopic and kinetic studies of interactions of calf spleen purine nucleoside phosphorylase with 8-azaguanine, and its 9-(2-phosphonylmethoxyethyl) derivative
Wierzchowski, Jacek,Stepniak, Katarzyna,Bzowska, Agnieszka,Shugar, David
, p. 459 - 464 (2008/02/02)
Spectroscopic and kinetic studies of interactions of calf spleen purine nucleoside phosphorylase with 8-azaguanine, an excellent fluorescent/fluorogenic substrate for the synthetic pathway of the reaction, and its 9-(2-phosphonylmethoxyethyl) derivative, a bisubstrate analogue inhibitor, were carried out. The goal was to clarify the catalytic mechanism of the enzymatic reaction by identification of ionic/tautomeric forms of these ligands in the complex with PNP. Copyright Taylor & Francis, Inc.
