eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-09-25 13 3 1383 1388 10.13005/bbra/2280 15960 article Mohd. Imran 1 Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Northern Border University, Rafha - 91911, P.O. BOX 840, Kingdom of Saudi Arabia. In continuation of our work related to the identification of pyridazinone derivatives as Angiotensin Converting Enzyme (ACE) inhibitors, we report herein the molecular modelling studies and ACE inhibitory activity of some 4-benzylidene-2-substitutedbenzoyl-6-phenyl-4,5-dihydropyridazin-3(2H)-ones (3a-3l). These compounds were prepared by the reaction of 2-(2-substitutedbenzoyl)-6-phenyl-4,5-dihydropyridazin-3(2H)-ones (2a-2l) with benzaldehyde. Molecular docking studies were carried out to determine the most active inhibitor of the Angiotensin Converting Enzyme (ACE). The compound (3a) was identified as the most active inhibitor of the ACE. The in vitro enzymatic ACE inhibitory activity of the compound (3a) using Dojindo ACE Kit-WST test kit revealed that the compound (3a) had IC₅₀ value of 4.40 μg/mL, wherein the standard drug Lisinopril had IC₅₀ value of 0.99 μg/mL. The comparison of the binding pattern of Lisinopril and the compound (3a) with the active sites of the ACE enzyme revealed that the incorporation of free amino groups and//or free carboxylic acid groups in the chemical structure of the compounds (3a-3l) may provide more active and potent ACE inhibitors. https://www.biotech-asia.org/vol13no3/molecular-modelling-studies-and-angiotensin-converting-enzyme-inhibitory-activity-of-some-4-benzylidene-2-substitutedbenzoyl-6-phenyl-45-dihydropyridazin-32h-ones/ Molecular modelling ACE inhibitor Antihypertensive Pyridazinones.