ABSTRACT
A series of 6-hydrazinopurine 2'-methyl ribonucleosides was synthesized and tested for its inhibitory activity against the hepatitis C virus (HCV). The lack of antiviral activity of these nucleosides was associated with a poor affinity for adenosine kinase, which prompted us to synthesize several of their 5'-monophosphate prodrugs. Some of these prodrugs exhibited more than 1000-fold improvement in anti-HCV activity when compared to their parent nucleosides (EC(50) of 24 nM vs 92 microM for the parent).
Subject(s)
Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacology , Hepacivirus/genetics , Hepatitis C/drug therapy , Phosphates/chemistry , Ribonucleosides/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Virus Replication/drug effects , Chemistry, Pharmaceutical/methods , Drug Design , Humans , Models, Chemical , Molecular Conformation , ProdrugsABSTRACT
A new series of heterobase-modified 2'-C-methyl ribonucleosides was synthesized and tested as inhibitors of hepatitis C virus (HCV) RNA replication. The nucleosides showed a weak inhibitory activity in a HCV replicon system (EC(50)=92 microM) and did not exhibit any cytotoxicity (CC(50)>300 microM). Cyclic monophosphate (cMP) prodrugs of the same nucleosides were synthesized and also tested in the HCV replicon system. Prodrugs exhibited strong potency (EC(50)=0.008 microM) without significant cytotoxicity (CC(50)>50 microM).
Subject(s)
Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacology , Chemistry, Pharmaceutical/methods , Hepacivirus/genetics , Hepatitis C/drug therapy , Nucleotides, Cyclic/chemistry , Prodrugs/chemical synthesis , Ribonucleosides/chemistry , Virus Replication/drug effects , Drug Design , Humans , Models, Chemical , Molecular ConformationABSTRACT
Several Toyocamycin (4) analogues were examined for their ability to inhibit HCV RNA in a replicon assay. Among the compounds examined 4-methylthio (18) and 5-carboxamide oxime derivatives (23 and 27) of Toyocamycin were found to have good activity and selectivity.
Subject(s)
Antiviral Agents/chemical synthesis , Toyocamycin/chemical synthesis , Antiviral Agents/pharmacology , Hepatitis C/drug therapy , Hepatitis C/metabolism , Hepatitis C/virology , Humans , Magnetic Resonance Spectroscopy , Molecular Structure , Pyrimidine Nucleosides/chemistry , Pyrimidines/chemistry , Pyrroles/chemistry , RNA-Dependent RNA Polymerase/antagonists & inhibitors , RNA-Dependent RNA Polymerase/metabolism , Toyocamycin/analogs & derivatives , Toyocamycin/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/metabolismABSTRACT
The synthesis of pyrazolo[4,3-d]pyrimidine nucleoside library using solid-phase parallel synthesis methodology is described. Glycosylation of the trimethylsilyl (TMS) derivative of 1- and 2-(methyl)-1H and 2H-pyrazolo[4,3-d]pyrimidine-5,7-(4H, 6H)-dione (5) with 1-O-acetyl-2,3,5-tri-O-benzoyl-D-ribofuranose in the presence of TMS triflate provided two novel protected nucleosides 6 and 7. The structures of 6 and 7 were assigned by 1H and 2D NMR experiments. Nucleosides 6 and 7 were then transformed to the key intermediates 12 and 15 respectively. Reaction of 12 and 15 with MMTCl resin in the presence of 2,6-lutidine afforded the necessary scaffolds B and C. Different amines (96) were introduced selectively by nucleophilic substitution on scaffolds B and C using solid-phase parallel semi-automated synthesizer. Cleavage of the products from the solid support with 30% HFIP in a parallel fashion yielded nucleoside libraries simultaneously, and they were analyzed and characterized by high-throughput LC-MS.
