Structure‐based design of new N ‐benzyl‐piperidine derivatives as multitarget‐directed AChE/BuChE inhibitors for Alzheimer's disease

Abstract The pathogenic complexity of Alzheimer's disease (AD) demands the development of multitarget‐directed agents aiming at improving actual pharmacotherapy. Based on the cholinergic hypothesis and considering the well‐established role of butyrylcholinesterase (BuChE) in advanced stages of AD, the chemical structure of the acetylcholinesterase (AChE) inhibitor drug donepezil ( 1 ) was rationally modified for the design of new N ‐benzyl‐piperidine derivatives ( 4a−d ) as potential multitarget‐direct AChE and BuChE inhibitors. The designed analogues were further studied through the integration of in silico and in vitro methods. ADMET predictions showed that 4a−d are anticipated to be orally bioavailable, able to cross the blood‐brain barrier and be retained in the brain, and to have low toxicity. Computational docking and molecular dynamics indicated the formation of favorable complexes between 4a−d and both cholinesterases. Derivative 4a presented the lowest binding free energy estimation due to interaction with key residues from both target enzymes (−36.69 ± 4.47 and −32.23 ± 3.99 kcal/mol with AChE and BuChE, respectively). The in vitro enzymatic assay demonstrated that 4a was the most potent inhibitor of AChE (IC 50 2.08 ± 0.16 µM) and BuChE (IC 50 7.41 ± 0.44 µM), corroborating the in silico results and highlighting 4a as a novel multitarget‐directed AChE/BuChE inhibitor.