SYNTHETIC NUCLEOSIDES

[Synthetic studies of imidazole C-nucleosides toward biofunctional molecules].

Synthetic studies of C4-linked imidazole C-nucleosides toward biofunctional molecules are described, in which the following items are covered. 1) Stereoselective synthesis of imidazole C- and pyrazole C-nucleosides via diazafulvene intermediates. 2) Synthesis of tetrahydrofuranylimidazoles using a PhSe group efficiently and its application to the new human histamine H(3) receptor (hH(3)R) agoni...

Cytidine nucleosides II. Photochemical synthesis of 5-alkylcytidine nucleosides

5-Alkylcytidine nucleosides were synthesized via a photocoupling reaction. 5-Propylcytidine and 5-propyl-2-deoxycytidine have been prepared through the reduction of 5-(3-propenyl)cytidine and its 2'-deoxy derivative, which in turn were prepared by photoirradiation of cytidine or 2'-deoxycytidine in the presence of 3-iodopropene. 5-(2-Hydroxyethyl)cytidine and its derivatives were obtained from ...

Inhibition by Nucleosides

FUdR is readily phosphorolyzed by thymidine phosphorylase (EC 2.4.2.4) purified from Escherichia coli (22), and it also can be cleaved by uridine phosphorylase (EC 2.4.2.3) purified from Ehrlich ascite tumor (21). It has been suggested that this breakdown may be a reason for the limited therapeutic effect of FUdR, and various attempts to find conditions that prevent phosphorolysis of FUdR have ...

Nucleosides: Metabolites and Drugs

movement of numerous nonlipophilic compounds across cell membranes and are likely to have evolved soon after the appearance of the lipid-based biological membrane. Any substance that must enter or leave a eukaryotic or prokaryotic cell and that is not soluble in lipid or small enough to diffuse between the constituent molecules that make up a membrane requires a specialized transport mechanism ...

Prebiotic Synthesis of Pyrimidine Nucleosides