Cyclic (hydroxyphosphinyl)acyl dipeptides: a new class of angiotensin converting enzyme inhibitors.

Conformationally constrained phenylbutyl(hydroxyphosphinyl)acyl dipeptides are potent inhibitors of angiotensin converting enzyme. The activity enhancement obtained by introducing conformational constraint into these molecules is greater than for related sulfhydryl and carboxyl analogs. The results are interpreted in terms of a binding model which optimally positions both zinc binding and hydrophobic groups for active site binding.