Radiosensitizing Nucleosides

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

Practical syntheses of antiviral nucleosides

Guanosine produced by fermentation is one of the nucleosides most readily available on an industrial scale. We have recently developed several processes leading to known antiviral agents starting with guanosine. The processes involve enzymatic transglycosylation for stavudine (d4T), chemical transpurination for acyclovir and ganciclovir, and novel alkylauon for penciclovir and famciclovir. Intr...