Dual angiotensin converting enzyme/thromboxane synthase inhibitors.

A variety of compounds were prepared to determine whether dual angiotensin converting enzyme (ACE)/thromboxane synthase (TxS) inhibition could be obtained in the same molecule. These compounds would be used to explore the concept that a dual inhibitor would have superior antihypertensive activity in the spontaneous hypertensive rat compared to an ACE inhibitor. Potent in vitro dual ACE and TxS inhibition was obtained in the same molecule with five series of compounds. Potent blood pressure lowering in the SHR was observed after oral administration of 8b and 11. However, a correlation between blood pressure lowering and the A1 pressor response inhibition was not observed. The blood pressure-lowering actions of enalapril were significantly potentiated by concurrent administration of 3, a thromboxane synthase inhibitor. Analysis of the area under the curve for 24 h showed nearly a doubling of the blood pressure-lowering effect.

Enkephalinase inhibitors. 1. 2,4-Dibenzylglutaric acid derivatives.

The synthesis of two new series of dicarboxylic acid dipeptides and two sulfhydryl-containing inhibitors are described. The in vitro enkephalinase inhibition data and some in vivo analgesic data are presented for these compounds. For the dibenzylglutaric acid series structure-activity relationships and in vivo analgesic activity are discussed. The reverse amides, i.e., 4-amino-2,4-dibenzylbutyric acid derivatives, are also discussed. Two sulfhydryl-containing inhibitors showed good in vivo potency in the mouse jump-latency hot-plate test after peripheral administration at moderate low doses.

Angiotensin converting enzyme inhibitors: N-substituted D-glutamic acid gamma dipeptides.

The preparation of two series of N-carbobenzoxy-gamma-D-glutamyl secondary 2S amino acids and (N-substituted gamma-D-glutamyl)indoline-2(S)-carboxylic acid dipeptides is described. In vitro inhibition of angiotensin converting enzyme (ACE) is reported for each compound, and the structure-activity relationship is discussed. Oral and iv inhibition of AI pressor response in vivo of selected compounds in Table II is also discussed. The most potent compounds in vitro, 3 and 6a, had an ACE IC50 of 7 and 2.7 X 10(-9) M, respectively.

Angiotensin converting enzyme inhibitors: N-substituted monocyclic and bicyclic amino acid derivatives.

The synthesis of N-(3-mercaptopropionyl)-N-arylglycines (14a-x),- N-arylalanines (15a,b),-N-cycloalkylglycines (16a-k), and -1,2,3,4-tetrahydroisoquinoline-3-carboxylic acids (17a-d), -1,2,3,4-tetrahydroquinoline-2-carboxylic acids (18a-f), and -indoline-2-carboxylic acids (19a-k) is described. In vitro inhibition of angiotensin converting enzyme (ACE) is reported for each compound, and the structure--activity relationship for each series is discussed. The in vivo inhibition of ACE and antihypertensive effects of representative compounds from each series are discussed. The most potent compound, 19d, had an in vitro ACE IC50 of 2.6 X 10(-9) M and lowered blood pressure in spontaneous hypertensive rats 85 mm at a dose of 10 mg/kg po.

Angiotensin converting enzyme inhibitors: 1-glutarylindoline-2-carboxylic acids derivatives.

The preparation of a series of 1-glutarylindoline-2(S)-carboxylic acid derivatives, 6a-v and 21a-c, is described. The above compounds were tested for inhibition of angiotensin converting enzyme. The structure-activity relationship of the series is also discussed. Compound 6u, the most potent member of the series, had an in vitro IC50 of 4.8 X 10(-9) M. Compound 6v, an ethyl ester of 6u, lowered blood pressure 70 mm in spontaneous hypertensive rats at an oral dose of 30 mg/kg.