In-vitro screening and docking study of fosinopril and its analogs

Hypertension is the most common cardiovascular disease. The prevalence of hypertension increases with advancing age; for example, about 50% of people between the ages of 60 and 69 years old have hypertension, and the prevalence is further increased beyond age of 70. Many angiotensin converting enzyme (ACE) inhibitors are known to be useful in the treatment of hypertension. The search for ACE inhibitors that lacked the sulfhydryl group also leads to the investigation of phosphorus containing compounds. The phosphinic acid is capable of binding to ACE in a manner similar to enalapril. The interaction of the zinc atom with the phosphinic acid is similar that is seen with sulfhydryl groups The purpose of study is to design some derivatives of ACE Inhibitors like fosinopril, evaluate its invitro activity and carry out its docking studies to find the derivative with highest potency. Six analogs of fosinopril were given as gift samples by a pharmaceutical industry. The method of invitro study relies on spectrophotometric determination of hippuric acid, based on colorimetric reaction of hippuric acid with benzene sulfonyl chloride. Analog A2 was found to possess highest activity ( minimum IC50 value) followed by Fosinopril, Al, A4, A3, A5, and A6 respectively. GRIP batch docking study for all six compounds was carried out by using crystal structure of ACE as receptor, to screen them based on the dock score using the software vLife MDS 3.0. Analog A2 was found to have minimum dock score ( binding with the receptor by minimum energy) indicating highest activity.