Therapeutic investigations of novel indoxyl-based indolines: A drug target validation and Structure-Activity Relationship of angiotensin-converting enzyme inhibitors with cardiovascular regulation and thrombolytic potential.

A family of 12 members of Naphthalene-2-ol-indolin-2-one-thiocarbamides (5a-l) with pharmacological potentials of cardiovascular modulator were efficiently synthesized and evaluated. These compounds show inhibitory activity on angiotensin-converting enzyme (ACE), which is a principal constituent of the renin-angiotensin system and causative source for hypertension (HTN) (elevated blood pressure) and congestive heart failure (CHF), a parameter that was tested in this report. Prior to this, to get more insight into the binding mode and inhibition of human ACE C-domain (PDB ID: 2XY9) and N-domain (PDB ID: 3NXQ) compounds 5a-l was docked into the active site of them. The established inhibitory constant (Ki) (range 40-500 nM) and least binding affinities (-18.52 to -30.57 kcal/mol) indicated the therapeutic selectivity of compounds 5a-l towards ACE C-domain inhibition over ACE N-domain. The cytotoxicity effect of most potent compounds among 5a-l were tested in normal breast cells and MCF-7 cell lines. Simultaneously, H2O2 induced antioxidant and DNA damage assessment was executed. Eventually, a thrombolytic activity followed by a human red blood cell (HRBC) membrane stabilization study to ensure the relaxation of blood and stabilization of RBC was executed. Structure-Activity Relationship (SAR) study discloses the potential of 5c, 5h, and 5k as cardiovascular protective therapeutic agents among 5a-l.