Water-soluble renin inhibitors: design of a subnanomolar inhibitor with a prolonged duration of action

Abstract
Incorporation of nonreactive polar functionalities at the C- and N-termini of renin inhibitors led to the development of a subnonamolar compound (21) with millimolar solubility. This inhibitor demonstrated excellent efficacy and a long duration of action upon intravenous administration to monkeys. While activity was also observed intraduodenally, a comparison of the blood pressure responses indicated low bioavailability. Subsequent experiments in rats showed that, although the compound was absorbed from the gastrointestinal tract, extensive liver extraction severly limited bioavailability.