β-D-2'-C-Methyl-2,6-diaminopurine Ribonucleoside Phosphoramidates are Potent and Selective Inhibitors of Hepatitis C Virus (HCV) and Are Bioconverted Intracellularly to Bioactive 2,6-Diaminopurine and Guanosine 5'-Triphosphate Forms

J Med Chem. 2015 Apr 23;58(8):3445-58. doi: 10.1021/jm501874e. Epub 2015 Apr 7.

Abstract

The conversion of selected β-D-2,6-diaminopurine nucleosides (DAPNs) to their phosphoramidate prodrug (PD) substantially blocks the conversion to the G-analog allowing for the generation of two bioactive nucleoside triphosphates (NTPs) in human hepatocytes. A variety of 2'-C-methyl DAPN-PDs were prepared and evaluated for inhibition of HCV viral replication in Huh-7 cells, cytotoxicity in various cell lines, and cellular pharmacology in both Huh-7 and primary human liver cells. The DAPN-PDs were pan-genotypic, effective against various HCV resistant mutants, and resistant variants could not be selected. 2'-C-Me-DAPN-TP and 2'-C-Me-GTP were chain terminators for genotype 1b HCV-pol, and single nucleotide incorporation assays revealed that 2'-C-Me-DAPN-TP was incorporated opposite U. No cytotoxicity was observed with our DAPN-PD when tested up to 50 μM. A novel, DAPN-PD, 15c, has been selected for further evaluation because of its good virologic and toxicologic profile and its ability to deliver two active metabolites, potentially simplifying HCV treatment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 2-Aminopurine / analogs & derivatives*
  • 2-Aminopurine / chemistry
  • 2-Aminopurine / metabolism
  • 2-Aminopurine / pharmacology
  • Amides / chemistry
  • Amides / metabolism
  • Amides / pharmacology
  • Antiviral Agents / chemistry*
  • Antiviral Agents / metabolism
  • Antiviral Agents / pharmacology*
  • Cell Line
  • Cells, Cultured
  • Guanosine Triphosphate / chemistry*
  • Guanosine Triphosphate / metabolism
  • Guanosine Triphosphate / pharmacology*
  • Hepacivirus / drug effects*
  • Hepacivirus / genetics
  • Hepatitis C / drug therapy
  • Humans
  • Methylation
  • Phosphoric Acids / chemistry
  • Phosphoric Acids / metabolism
  • Phosphoric Acids / pharmacology
  • Prodrugs / chemistry
  • Prodrugs / metabolism
  • Prodrugs / pharmacology
  • Ribonucleosides / chemistry
  • Ribonucleosides / metabolism
  • Ribonucleosides / pharmacology

Substances

  • Amides
  • Antiviral Agents
  • Phosphoric Acids
  • Prodrugs
  • Ribonucleosides
  • 2-Aminopurine
  • 2,6-diaminopurine
  • Guanosine Triphosphate
  • phosphoramidic acid