Design, Synthesis and Evaluation of Novel 2-Hydroxypyrrolobenzodiazepine-5,11-dione Analogues as Potent Angiotensin Converting Enzyme (ACE) Inhibitors.

Under the guidance of combination of traditional Chinese medicine chemistry (CTCMC), this study describes the preparation of a phenolic acid/dipeptide/borneol hybrid consisting of phenolic acid and a bornyl moiety connected to the dipeptide N -terminal and C -terminal respectively. It also evaluates their angiotensin converting enzyme (ACE) inhibitory and synergistic antihypertensive activities. Briefly, a series of novel 2-hydroxypyrrolobenzodiazepine-5,11-dione analogues were prepared and investigated for their ability to inhibit ACE. The influence of the phenolic acid and bornyl moiety on subsite selectivity is also demonstrated. Among all the new compounds, two compounds- 7a and 7g -reveal good inhibition potency in in vitro ACE-inhibitory tests. Interestingly, favorable binding results in molecular docking studies also supported the in vitro results. Additionally, the bioassay showed that oral administration of the two compounds displayed high and long-lasting antihypertensive activity both in acute antihypertensive tests and in therapeutic antihypertensive tests by non-invasive blood pressure measurements in spontaneously hypertensive rats.