Relaxant activity of 2-(substituted phenyl)-1H-benzimidazoles on isolated rat aortic rings: design and synthesis of 5-nitro derivatives

Life Sci. 2006 Jun 27;79(5):430-5. doi: 10.1016/j.lfs.2006.01.019. Epub 2006 Feb 17.


The relaxant activity of 2-(o, p-substituted phenyl)-1H-benzimidazole derivatives with various 5- and 6-position substituents (-H, -CH3, -NO2, -CF3), namely 1-7, was recorded using the in vitro rat aorta ring test. Compounds 3 and 6 [2-(5-nitro-1H-benzimidazol-2-yl)phenol and 2-(4-methoxyphenyl)-5-nitro-1H-benzimidazole] were prepared using a short route, and were the most potent compounds of the series, showing IC50 value of 0.95 and 1.41 (with endothelium) and 2.01 and 3.61 microM (without endothelium), respectively. Studying further structure-activity relationships through the use of bioisosteric substitution in these benzimidazole derivatives should provide novel vasorelaxant leads and possibly against hypertensive diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aorta / drug effects*
  • Benzimidazoles / chemical synthesis*
  • Benzimidazoles / chemistry
  • Benzimidazoles / pharmacology*
  • Dose-Response Relationship, Drug
  • Endothelium-Dependent Relaxing Factors / chemical synthesis*
  • Endothelium-Dependent Relaxing Factors / chemistry
  • Endothelium-Dependent Relaxing Factors / pharmacology*
  • In Vitro Techniques
  • Male
  • Rats
  • Rats, Wistar


  • Benzimidazoles
  • Endothelium-Dependent Relaxing Factors
  • benzimidazole