Nonpeptidic angiotensin II AT1 receptor antagonists derived from 6-substituted aminocarbonyl and acylamino benzimidazoles.

Both 6-substituted aminocarbonyl and acylamino benzimidazole derivatives were designed and synthesized as nonpeptidic angiotensin II AT1 receptor antagonists. Compounds 6f, 6g, 11e, 11f, 11g, and 12 showed nanomolar AT1 receptor binding affinity and high AT1 receptor selectivity over AT2 receptor in a preliminary pharmacological evaluation. Among them, the two most active compounds 6f (AT1 IC50 = 3 nM, AT2 IC50 > 10,000 nM, PA2 = 8.51) and 11g (AT1 IC50 = 0.1 nM, AT2 IC50 = 149 nM, PA2 = 8.43) exhibited good antagonistic activity in isolated rabbit aortic strip functional assay. In addition, they were orally active AT1 receptor antagonists in spontaneous hypertensive rats.

Design, synthesis and biological activity of 6-substituted carbamoyl benzimidazoles as new nonpeptidic angiotensin II AT1 receptor antagonists.

A series of 6-substituted carbamoyl benzimidazoles were designed and synthesised as new nonpeptidic angiotensin II AT(1) receptor antagonists. The preliminary pharmacological evaluation revealed a nanomolar AT(1) receptor binding affinity for all compounds in the series, and a potent antagonistic activity in an isolated rabbit aortic strip functional assay for compounds 6f, 6g, 6h and 6k was also demonstrated. Furthermore, evaluation in spontaneous hypertensive rats and a preliminary toxicity evaluation showed that compound 6g is an orally active AT(1) receptor antagonist with low toxicity.

Design, synthesis and biological evaluation of 6-substituted aminocarbonyl benzimidazole derivatives as nonpeptidic angiotensin II AT1 receptor antagonists.

A series of 6-substituted aminocarbonyl benzimidazole derivatives were designed and synthesized as nonpeptidic angiotensin II AT(1) receptor antagonists. The preliminary pharmacological evaluation revealed nanomolar AT(1) receptor binding affinity and good AT(1) receptor selectivity over AT(2) receptor for all compounds of the series, a potent antagonistic activity in isolated rabbit aortic strip functional assay for compounds 6b, 6d and 6i was also demonstrated. Furthermore, evaluation in spontaneous hypertensive rats and a preliminary toxicity evaluation showed that compound 6i is an orally active AT(1) receptor antagonist with low toxicity.

Pharmacophore modeling of dual angiotensin II and endothelin A receptor antagonists.

Three-dimensional pharmacophore models were generated for AT1 and ET(A) receptors based on highly selective AT1 and ET(A) antagonists using the program Catalyst/HipHop. Both the best pharmacophore model for selective AT1 antagonists (Hypo-AT(1)-7) and ETA antagonists (Hypo-ET(A)-1) were obtained through a careful validation process. All five features contained in Hypo-AT(1)-7 and Hypo-ET(A)-1 (hydrogen-bond acceptor (A), hydrophobic aliphatic (Z), negative ionizable (N), ring aromatic (R), and hydrophobic aromatic (Y)) seem to be essential for antagonists in terms of binding activity. Dual AT1 and ET(A) receptor antagonists (DARAs) can map to both Hypo-AT(1)-7 and Hypo-ET(A)-1, separately. Comparison of Hypo-AT(1)-7 and Hypo-ET(A)-1, not only AT1 and ET(A) antagonist pharmacophore models consist of essential features necessary for compounds to be highly active and selective toward their corresponding receptor, but also have something in common. The results in this study will act as a valuable tool for designing and researching structural relationship of novel dual AT1 and ET(A) receptor antagonists.