RESUMEN
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).
Asunto(s)
Antivirales/síntesis química , Antivirales/farmacología , Hepacivirus/genética , Hepatitis C/tratamiento farmacológico , Fosfatos/química , Ribonucleósidos/química , Proteínas no Estructurales Virales/antagonistas & inhibidores , Replicación Viral/efectos de los fármacos , Química Farmacéutica/métodos , Diseño de Fármacos , Humanos , Modelos Químicos , Conformación Molecular , ProfármacosRESUMEN
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.
