Synthesis and biological evaluation of 1,2,4-trisubstituted imidazoles and 1,3,5-trisubstituted pyrazoles as inhibitors of transforming growth factor beta type 1 receptor (ALK5)

Bioorg Med Chem Lett. 2009 Aug 15;19(16):4868-72. doi: 10.1016/j.bmcl.2009.04.066. Epub 2009 Apr 20.

Abstract

Two series of nitrogenous heterocycle compounds--1,2,4-trisubstituted imidazoles and 1,3,5-trisubstituted pyrazoles have been synthesized and evaluated for their ALK5 inhibitory activity and cytotoxicity in TGFbeta-Smad2 assay and MTT assay, respectively. The ALK4/5/7 inhibitory activity of some compound was also evaluated in ALK4/5/7 autophosphorylation assays. Compounds 6c and 14c showed relatively potent ALK5 inhibition while weak cytotoxicity. At the same time, compounds 6c and 14c display relatively better ALK5 selectivity versus ALK4/ALK7 (nearly 10-fold) compared with SB431542, a well known ALK5 inhibitor. Compound 6g2 proved to be a moderately selective ALK4 inhibitor versus ALK5 and ALK7 (>10-fold). The binding mode of 14c generated by flexible docking study shows that 14c fits well into the site cavity of ALK5 by forming several tight interactions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzamides / pharmacology
  • Binding Sites
  • Cell Line
  • Crystallography, X-Ray
  • Dioxoles / pharmacology
  • Humans
  • Imidazoles / chemical synthesis
  • Imidazoles / chemistry*
  • Imidazoles / toxicity
  • Phosphorylation
  • Protein Kinase Inhibitors / chemical synthesis*
  • Protein Kinase Inhibitors / chemistry
  • Protein Kinase Inhibitors / pharmacology
  • Protein Serine-Threonine Kinases / antagonists & inhibitors*
  • Protein Serine-Threonine Kinases / metabolism
  • Pyrazoles / chemical synthesis
  • Pyrazoles / chemistry*
  • Pyrazoles / toxicity
  • Receptor, Transforming Growth Factor-beta Type I
  • Receptors, Transforming Growth Factor beta / antagonists & inhibitors*
  • Receptors, Transforming Growth Factor beta / metabolism
  • Structure-Activity Relationship

Substances

  • 4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide
  • Benzamides
  • Dioxoles
  • Imidazoles
  • Protein Kinase Inhibitors
  • Pyrazoles
  • Receptors, Transforming Growth Factor beta
  • Protein Serine-Threonine Kinases
  • Receptor, Transforming Growth Factor-beta Type I
  • TGFBR1 protein, human