Derivatives of oxoisoaporphine alkaloids: A novel class of selective acetylcholinesterase inhibitors

A series of 9-aminoalkanamido-1-azabenzanthrones derviatives (3a–i Ar–NHCO(CH2)nNR1R2) and their quaternary methiodide salts (4a–g Ar–NHCO(CH2)nN+(CH3)R1R2I−) were designed and synthesized as acetylcholinesterase (AChE) or butyrylcholinesterase (BuChE) inhibitors. The synthetic compounds exhibited high AChE inhibitory activity with IC50 values in the nanomolar range and high selectivity for AChE over BuChE (45- to 1980-fold). The structure–activity relationships (SARs) were discussed.