A New Class of Benzo[b]thiophene-chalcones as Cholinesterase Inhibitors: Synthesis, Biological Evaluation, Molecular Docking and ADME Studies

In this study, heterocyclic compounds containing a benzothiophene scaffold were designed and synthetized, and their inhibitory activity against cholinesterases (ChE) and the viability of SH- SY5Y cells have been evaluated. Benzothiophenes 4a–4i and benzothiophene-chalcone hybrids 5a–5i were tested against both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), revealing interesting structure–activity relationships. In general, benzothiophene–chalcone hybrids from series 5 proved to be better inhibitors of both enzymes, with compound 5f being the best AChE inhibitor (IC50 = 62.10 μM) and compound 5h being the best BChE inhibitor (IC50 = 24.35 μM), the last one having an IC50 similar to that of galantamine (IC50 = 28.08 μM), the reference compound. The in silico ADME profile of the compounds was also studied. Molecular docking calculations were carried out to analyze the best binding scores and to elucidate enzyme–inhibitors’ interactions.