QSAR of smooth muscle relaxation by 2,5-substituted-benzimidazole derivatives

Abstract

Quantitative structure-activity anlayses were carried out for in vitro relaxant actions of a series of 2,5-substituted-benzimidazoles in rat duodenal smooth muscle. Analyses of simple and multiple linear regression models revealed modest to good correlations between the relaxant activity and structural properties of the benzimidazole derivatives such as steric, hydrophobic and electronic parameters. In the present study, it was observed that, as a collective property, parachor log (Par)+partition coefficient log (P) gives good results using either apparent affinity constant (pD2) or intrinsic activity (?(E)) as the predicted values. In this case, it was supposed that both the lipophilicity and the surface tension of molecules are responsible for the activity observed.