Hybrids of oxoisoaporphine-tacrine congeners: Novel acetylcholinesterase and acetylcholinesterase-induced β-amyloid aggregation inhibitors

A series of dual binding site acetylcholinesterase (AChE) inhibitors have been designed, synthesized, and tested for their ability to inhibit AChE, butyrylcholinesterase (BChE), AChE-induced and self-induced β -amyloid (A β ) aggregation. The new hybrids consist of a unit of 1-azabenzanthrone and a tacrine or its congener, connected through an oligomethylene linker containing an amine group at variable position. These hybrids exhibit high AChE inhibitory activity with IC 50 values in the nanomolar range in most cases. Moreover, five out of the 12 hybrids of this series, particularly those bearing a tetrahydroacridine moiety, exhibit a significant in vitro inhibitory activity toward the AChE-induced and self-induced A β aggregation, which makes them promising anti-Alzheimer drug candidates.