Design, Synthesis, Biological Evaluation, and Computational Studies of N-benzoylethylenediamine Derivatives As Cholinesterase Inhibitors

In this study, a series of N-benzoylethylenediamine derivatives (16a-16u) was rationally designed and successfully synthesized using a strategy that combines cholinesterase (ChE) inhibition with antioxidant activity. The inhibitory activities of all compounds against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), along with their antioxidant capacity, were systematically evaluated in vitro. Most compounds exhibited moderate to potent inhibition against both enzymes. Notably, compound 16 L showed the best dual inhibitory activity, with IC50 values of 1.71 µM for AChE and 2.38 µM for BuChE, both superior to those of the reference drug, galantamine. (AChE: IC50 = 5.17 µM, BuChE: IC50 = 11.06 µM). Furthermore, the DPPH radical scavenging assay indicated that compound 16a exhibited the strongest antioxidant activity (IC50 = 27.69 µM), which was slightly stronger than that of the positive control ascorbic acid (IC50 = 32.59 µM). Enzyme kinetic studies revealed that compound 16 L acts as a mixed-type inhibitor of AChE. Molecular docking results further demonstrated that 16 L interacts with both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE, consistent with the kinetic data; however, for BuChE, 16 L interacts only with the CAS. Molecular dynamics (MD) simulations confirmed the stability of the 16 L-AChE/BuChE complexes. Collectively, these findings validate compound 16 L’s research value as a dual inhibitor of AChE and BuChE.