Structure-based discovery of pyrazolobenzothiazine derivatives as inhibitors of hepatitis C virus replication

J Med Chem. 2013 Mar 28;56(6):2270-82. doi: 10.1021/jm301643a. Epub 2013 Mar 7.

Abstract

The NS5B RNA-dependent RNA polymerase is an attractive target for the development of novel and selective inhibitors of hepatitis C virus replication. To identify novel structural hits as anti-HCV agents, we performed structure-based virtual screening of our in-house library followed by rational drug design, organic synthesis, and biological testing. These studies led to the identification of pyrazolobenzothiazine scaffold as a suitable template for obtaining novel anti-HCV agents targeting the NS5B polymerase. The best compound of this series was the meta-fluoro-N-1-phenyl pyrazolobenzothiazine derivative 4a, which exhibited an EC50 = 3.6 μM, EC90 = 25.6 μM, and CC50 > 180 μM in the Huh 9-13 replicon system, thus providing a good starting point for further hit evolution.

Publication types

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

MeSH terms

  • Antiviral Agents / chemical synthesis
  • Antiviral Agents / chemistry
  • Antiviral Agents / pharmacology
  • Drug Design*
  • Hepacivirus / drug effects*
  • Hepacivirus / enzymology
  • Hepacivirus / physiology*
  • Models, Molecular
  • Protein Conformation
  • Pyrazoles / chemical synthesis
  • Pyrazoles / chemistry*
  • Pyrazoles / pharmacology*
  • Viral Nonstructural Proteins / antagonists & inhibitors
  • Viral Nonstructural Proteins / chemistry
  • Viral Nonstructural Proteins / metabolism
  • Virus Replication / drug effects*

Substances

  • Antiviral Agents
  • Pyrazoles
  • Viral Nonstructural Proteins
  • pyrazole
  • NS-5 protein, hepatitis C virus