α-Mercaptoacyl dipeptides that inhibit angiotensin converting enzyme and neutral endopeptidase 24.11

α-Mercaptoacyl dipeptides were prepared and found to inhibit angiotensin converting enzyme (ACE) and neutral endopeptidase 24.11 (NEP). Compounds with a proline as the C-terminal amino acid, and possessing the S-stereochemistry at the thiol bearing carbon were preferred for optimal ACE inhibition while, R-stereochemistry was preferred for optimal NEP inhibition. Compounds containing alternative amino acid residues at the C-terminal position displayed optimal dual ACE/NEP inhibition when the stereochemistry was ‘S’ at this carbon atom.