Cholinesterase Inhibitory Activity of Some semi-Rigid Spiro Heterocycles: POM Analyses and Crystalline Structure of Pharmacophore Site

Cholinesterase family consists of two sister enzymes; acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) which hydrolyze acetylcholine. Since deficit of acetylcholine has been evidenced in the patients of Alzheimer’s disease (AD), cholinesterase inhibitors are currently the most prescribed drug class for the treatment of AD. In the present study, five compounds (2-6) with spiro skeleton have been synthesized and tested for their inhibitory potential in vitro against AChE and BChE using ELISA microtiter plate assays at 25 mg/mL. Surprisingly 3/5 of the Spiro compounds tested exerted more than 50% inhibition against one of cholinesterases, the compound 5 showed 68.73±4.73% of inhibition toward AChE, when the compound 6 showed 56.17±0.83% of inhibition toward BChE being the most active hits.