Structure-activity relationships for 1-phenylbenzimidazoles as selective ATP site inhibitors of the platelet-derived growth factor receptor

J Med Chem. 1998 Dec 31;41(27):5457-65. doi: 10.1021/jm9804681.


1-Phenylbenzimidazoles are shown to be a new class of ATP-site inhibitors of the platelet-derived growth factor receptor (PDGFR). Structure-activity relationships (SARs) are narrow, with closely related heterocycles being inactive. A systematic study of substituted 1-phenylbenzimidazoles showed clear SARs. Substituents at the 4'- and 3'-positions of the phenyl ring are tolerated but do not significantly improve activity, while substituents at the 2'-position abolish it. Substituents in the 2-, 4-, and 7-positions of the benzimidazole ring (with the exception of 4-OH) also abolish activity. Most substituents at the 5- and 6-positions maintain or increase activity, with the 5-OH, 5-OMe, 5-COMe, and 5-CO2Me analogues being >10-fold more potent than the parent 1-phenylbenzimidazole. The 5-OMe analogue was both the most potent inhibitor, and showed the highest selectivity (50-fold) between PDGFR and FGFR isolated enzymes, and also a moderately effective inhibitor (IC50 = 1.9 microM) of PDGF-stimulated PDGFR autophosphorylation in rat aorta smooth muscle cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / antagonists & inhibitors*
  • Adenosine Triphosphate / metabolism
  • Animals
  • Aorta / cytology
  • Aorta / drug effects
  • Aorta / metabolism
  • Benzimidazoles / chemical synthesis*
  • Benzimidazoles / chemistry
  • Benzimidazoles / pharmacology
  • In Vitro Techniques
  • Muscle, Smooth, Vascular / cytology
  • Muscle, Smooth, Vascular / drug effects
  • Muscle, Smooth, Vascular / metabolism
  • Phosphorylation
  • Rats
  • Receptors, Fibroblast Growth Factor / metabolism
  • Receptors, Platelet-Derived Growth Factor / antagonists & inhibitors*
  • Receptors, Platelet-Derived Growth Factor / metabolism
  • Structure-Activity Relationship


  • Benzimidazoles
  • Receptors, Fibroblast Growth Factor
  • Adenosine Triphosphate
  • Receptors, Platelet-Derived Growth Factor