Synthesis, molecular docking, and biological evaluation of benzimidazole derivatives as selective butyrylcholinesterase inhibitors

Benzimidazole is an interesting pharmacophore, and its derivatives have been previously shown to possess cholinesterase inhibitory activity. In this study, benzimidazole derivatives were synthesized via a 4-step reaction scheme and screened for their acetylcholinesterase and butyrylcho-linesterase inhibitory activities. Among the synthesised compounds, three of them (5IIa, 5IIb, and 5IIc) exhibited potent, selective butyrylcholinesterase inhibition at a low micromolar level. The compounds did not show any significant cytotoxicity when tested against a panel of human cell lines. Moreover, the most active compound, 5IIc, was highly permeable across the blood-brain barrier. The structure-activity relationship and molecular interactions of the synthesized benzimidazole derivatives were also analysed and discussed.