Ribavirin antagonizes the in vitro anti-hepatitis C virus (HCV) activity of the pyrimidine nucleoside analogue 2'-C-methylcytidine, the active component of the experimental anti-HCV drug valopicitabine. In contrast, the combination of ribavirin with either the purine nucleoside analogue 2'-C-methyladenosine or the HCV protease inhibitor VX-950 resulted in an additive antiviral activity. These f...

Acyclic nucleoside analogues with carboxamido- or nitro-substituted heterocyclic bases have been evaluated for their possible use as universal bases in oligodeoxynucleotides. The acyclic moiety endows the constructs with enough flexibility to allow good base stacking. The 5-nitroindazole analogue afforded the most stable duplexes among the acyclic derivatives with the least spread in Tm versus ...

The question of Highly Active Antiretroviral Treatment (HAART) simplification is important due to long term toxicity and cost of HAART. Pro-viral HIV DNA associated with Peripheral Blood Mononuclear Cells (PBMC) is a marker of the HIV reservoir which is predictive of the evolution of HIV infection. It remains the only virological quantitative marker detectable during suppressive HAART. A provir...

Novel purine ribonucleoside analogues (9-13) containing a 4-substituted piperazine in the substituent at N(6) were synthesized and evaluated for their cytotoxicity on Huh7, HepG2, FOCUS, Mahlavu liver, MCF7 breast, and HCT116 colon carcinoma cell lines. The purine nucleoside analogues were analyzed initially by an anticancer drug-screening method based on a sulforhodamine B assay. Two nucleosid...

5-Hydroxyuridine triphosphate was synthesized and its effectiveness as substrate for deoxyribonucleic acid-dependent ribonucleic acid polymerase was determined. The analogue was incorporated into RNA to a very low extent as compared to naturally occurring nucleoside triphosphates, and it replaced uridine triphosphate to a much greater extent than any of the other nucleoside triphosphates. The a...

5-Hydroxyuridine triphosphate was synthesized and its effectiveness as substrate for deoxyribonucleic acid-dependent ribonucleic acid polymerase was determined. The analogue was incorporated into RNA to a very low extent as compared to naturally occurring nucleoside triphosphates, and it replaced uridine triphosphate to a much greater extent than any of the other nucleoside triphosphates. The a...

The absorption and fluorescence properties of formycin provide a useful tool in the analysis of enzyme-substrate interactions; we have therefore studied selected biochemical properties of formycin nucleotides. Formycin and its derivatives effectively substitute for the corresponding adenosine substrates in a wide variety of enzyme reactions. These include enzymes of nucleotide metabolism, RNA p...