cv-11194 and candesartan

Blockade of the action of angiotensin II (A II) is a target for development of novel antihypertensive agents. We have recently discovered a novel and potent nonpeptide AT1 selective A II receptor antagonists, benzimidazole-7-carboxylic acid derivatives (CV-11194 and CV-11974), which are more potent than DuP 753. The prodrug analogue (TCV-116) of CV-11974 is an orally active, highly potent and long-acting antihypertensive agent. The structure-activity relationships (SAR) of benzimidazole derivatives showed the importance of presence of a 7-carboxyl group for the potent and functionally non-competitive (insurmountable) A II antagonism. The interactions between the A II antagonist and receptor on the basis of SAR studies as well as A II receptor modeling are also described.

Topics: Angiotensin Receptor Antagonists; Animals; Antihypertensive Agents; Benzimidazoles; Biphenyl Compounds; Prodrugs; Structure-Activity Relationship; Tetrazoles

In order to improve the oral bioavailability (BA) of 2-butyl-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-benzimid azole - 7-carboxylic acid (3: CV-11194) and 2-ethoxy-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4- yl]methyl]-1H-benzimidazole-7-carboxylic acid (4: CV-11974), novel angiotensin II (AII) receptor antagonists, chemical modification to yield prodrugs has been examined. After selective tritylation of the tetrazole rings in 3 and 4, treatment of N-tritylated benzimidazole-7-carboxylic acids (6, 7) with a variety of alkyl halides, followed by deprotection with hydrochloric acid, afforded esters of 3 and 4. Mainly 1-(acyloxy)alkyl esters and 1-[(alkoxycarbonyl)oxy]alkyl esters, double ester derivatives, were synthesized. Their inhibitory effect on AII-induced pressor response in rats and oral BA were investigated. (Pivaloyloxy)methyl and (+/-)-1-[[(cyclohexyloxy)-carbonyl]oxy]ethyl esters of 3 and 4 showed marked increases in oral bioavailability which significantly potentiated the inhibitory effect of the parent compounds on AII-induced pressor response. Among them, (+/-)-1-[[(cyclohexyloxy)carbonyl]oxy]ethyl 2- ethoxy-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-benzimida zole- 7-carboxylate (10s, TCV-116) was selected as a candidate for clinical evaluation.

Topics: Administration, Oral; Angiotensin Receptor Antagonists; Animals; Benzimidazoles; Biological Availability; Biphenyl Compounds; Male; Prodrugs; Rats; Rats, Sprague-Dawley; Tetrazoles