Abstract: A class of cycloheptimidazolone compounds is described as angiotensin II antagonists for use in control of hypertension. Compounds of particular interest are those of the formula ##STR1## wherein each of R.sup.1 and R.sup.2 is independently selected from hydrido, alkyl, halo, alkanoyl, carboxyl, alkoxycarbonyl, phenyl, haloalkyl, alkoxyalkyl, formyl, cyano, alkoxy, phenoxy, phenylthio, alkylthio; wherein R.sup.3 is alkyl, alkenyl, alkynyl, hydroxyalkyl and alkoxyalkyl; wherein each of R.sup.5 through R.sup.13 is independently selected from hydrido, alkyl, haloalkyl, halo, nitro, cyano, hydroxy, alkoxy, alkylthio, aryl, aryloxy, arythio, and acidic groups such as carboxylic acid, with the proviso that at least one of R.sup.9 through R.sup.13 substituents is an acidic group; or a pharmaceutically-acceptable ester, amide or salt thereof.

Abstract: Synthesis and use of novel oligopeptides are described, many of which peptides contain one or several unnatural amino acids. These short linear peptide derivatives are characterized by the presence of a free sulfhydryl function. These compounds have a high affinity for the Atrial Natriuretic Peptide (ANP) receptor coupled to particulate guanylate cyclase. Such peptides are full agonists at the ANP receptor as demonstrated by the ability of the peptides to stimulate the production of cGMP and to relax smooth muscles in vitro. In accord with these observations, the compounds of the invention lower blood pressure in mammals. Preferred peptides are the following:Cys-Cha-Gly-Gly-Arg-Ile-Asp-Arg-Ile-GlyNH.sub.2 ; D-Cys-Cha-Gly-Gly-Arg-Ile-Asp-Arg-Ile-GlyNH.sub.2 ; L-Pen-Cha-Gly-Gly-Arg-Ile-Asp-Arg-Ile-GlyNH.sub.2 ; and Cys-Cha-Gly-Gly-Arg-Ile-Asp-Arg-IleNH.sub.2.

Abstract: A class of cycloheptimidazolone compounds is described as angiotensin II antagonists for use in control of hypertension. Compounds of particular interest are those of the formula ##STR1## wherein each of R.sup.1 and R.sup.2 is independently selected from hydrido, alkyl, halo, alkanoyl, carboxyl, alkoxycarbonyl, phenyl, haloalkyl, alkoxyalkyl, formyl, cyano, alkoxy, phenoxy, phenylthio, alkylthio; wherein R.sup.3 is alkyl, alkenyl, alkynyl, hydroxyalkyl and alkoxyalkyl; wherein each of R.sup.5 through R.sup.13 is independently selected from hydrido, alkyl, haloalkyl, halo, nitro, cyano, hydroxy, alkoxy, alkylthio, aryl, aryloxy, arythio, and acidic groups such as carboxylic acid, with the proviso that at least one of R.sup.9 through R.sup.13 substituents is an acidic group; or a pharmaceutically-acceptable ester, amide or salt thereof.