Discovery of New Butyrylcholinesterase Inhibitors and Evaluation of Their Biological Activity against Alzheimer's Disease

Alzheimer's disease (AD) is a degenerative disease of the central nervous system (CNS), which is relatively common in the elderly population and is the main cause of senile dementia. Its typical pathological features mainly lie in hyperphosphorylated tau proteins in the form of neurofibrillary tangles (referred to as tau tangles) and β-amyloid plaques. Using DrugCLIP website, we investigated the effects of butyrylcholinesterase (BChE) inhibitors on AD. From virtual screening, molecule W1 (inhibitory concentration (IC₅₀) = 0.63 ± 0.19 μM) was identified as the lead compound of this research. Subsequently, the lead compound molecule was obtained through chemical synthesis, and its structure was modified to synthesize and evaluate 21 derivatives. Derivatives W3 and W13 also showed micromolar-level BChE inhibitory activity (W3: IC₅₀ = 0.28 ± 0.14 μM, W13: IC₅₀ = 0.03 ± 0.02 μM), with W13 demonstrating superior inhibitory activity. The results of binding patterns demonstrated that both compounds can bind to the target and form multiple interactions with amino acid residues. From the enzyme kinetics results, it can be observed that both compounds were BChE inhibitors in a mixed manner, which was consistent with the docking results. Due to W3 not occupying the acyl-binding pocket, its activity was inferior to W13. In pharmacodynamic studies, W3 and W13 protected nerve cells from toxicity, hydrogen peroxide (H₂O₂), and Aβ_1-42 stimulation in vitro, reduced the production of Reactive Oxygen Species, and alleviated Aβ-induced cognitive impairment in mice. In addition, optimal compound W13 presented considerable pharmacokinetic properties, with a high oral bioavailability (80%). Moreover, it could penetrate the blood-brain barrier and take effect in the CNS. Therefore, these findings support further investigation of W3 and W13 as potential therapeutic candidates for advanced AD.