Vinylated linear P2 pyrimidinyloxyphenylglycine based inhibitors of the HCV NS3/4A protease and corresponding macrocycles

Bioorg Med Chem. 2014 Dec 1;22(23):6595-6615. doi: 10.1016/j.bmc.2014.10.010.

Abstract

With three recent market approvals and several inhibitors in advanced stages of development, the hepatitis C virus (HCV) NS3/4A protease represents a successful target for antiviral therapy against hepatitis C. As a consequence of dealing with viral diseases in general, there are concerns related to the emergence of drug resistant strains which calls for development of inhibitors with an alternative binding-mode than the existing highly optimized ones. We have previously reported on the use of phenylglycine as an alternative P2 residue in HCV NS3/4A protease inhibitors. Herein, we present the synthesis, structure-activity relationships and in vitro pharmacokinetic characterization of a diverse series of linear and macrocyclic P2 pyrimidinyloxyphenylglycine based inhibitors. With access to vinyl substituents in P3, P2 and P1' positions an initial probing of macrocyclization between different positions, using ring-closing metathesis (RCM) could be performed, after addressing some synthetic challenges. Biochemical results from the wild type enzyme and drug resistant variants (e.g., R155 K) indicate that P3-P1' macrocyclization, leaving the P2 substituent in a flexible mode, is a promising approach. Additionally, the study demonstrates that phenylglycine based inhibitors benefit from p-phenylpyrimidinyloxy and m-vinyl groups as well as from the combination with an aromatic P1 motif with alkenylic P1' elongations. In fact, linear P2-P1' spanning intermediate compounds based on these fragments were found to display promising inhibitory potencies and drug like properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Caco-2 Cells
  • Carrier Proteins / antagonists & inhibitors*
  • Carrier Proteins / metabolism
  • Cells, Cultured
  • Dipeptides / chemical synthesis
  • Dipeptides / chemistry
  • Dipeptides / pharmacology*
  • Dose-Response Relationship, Drug
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Macrocyclic Compounds / chemical synthesis
  • Macrocyclic Compounds / chemistry
  • Macrocyclic Compounds / pharmacology*
  • Models, Molecular
  • Molecular Structure
  • Protease Inhibitors / chemical synthesis
  • Protease Inhibitors / chemistry
  • Protease Inhibitors / pharmacology*
  • Pyrimidines / chemical synthesis
  • Pyrimidines / chemistry
  • Pyrimidines / pharmacology*
  • Structure-Activity Relationship
  • Viral Nonstructural Proteins / antagonists & inhibitors*
  • Viral Nonstructural Proteins / metabolism

Substances

  • Carrier Proteins
  • Dipeptides
  • Intracellular Signaling Peptides and Proteins
  • Macrocyclic Compounds
  • NS3 protein, hepatitis C virus
  • NS4A cofactor peptide, Hepatitis C virus
  • Protease Inhibitors
  • Pyrimidines
  • Viral Nonstructural Proteins