QSAR of peripheral benzodiazepine receptor ligand 2-phenylimidazo-[1,2-a]pyridine derivatives with physico-chemical parameters.

QSAR of the binding affinities of [2-phenylimidazo[1,2-a]pyridin-3-yl]acetamide derivatives (Fig. 1) with central and peripheral (from cortex and ovary) benzodiazepine receptors has been explored using physico-chemical parameters. Attempt has been made to explore the structural and/or physico-chemical requirements of the compounds that are responsible for the selective action against peripheral benzodiazepine receptors over central ones. The results indicate that the presence of bi-substitution on the carboxamido nitrogen, presence of substitutions at X and Y positions, especially, chloro substitution at X position, and presence of chloro substitution at Z position in presence of lipophilic X and/or Y substitutions increase selectivity for binding affinity with peripheral benzodiazepine receptors over central ones.