Structure-activity relationships and binding mode in the human acetylcholinesterase active site of pseudo-irreversible inhibitors related to xanthostigmine.

Structure-activity relationship studies on acetylcholinesterase (AChE) inhibitors were extended to newly synthesized compounds derived from the lead compound xantostigmine (1). The xanthone ring of compound 1 was replaced with several different scaffolds based on the benzopyran skeleton, linked to the tertiary amino nitrogen through an heptyloxy chain. These modifications resulted in 19 new compounds, most of them showing activity in the nanomolar-subnanomolar range. Docking and molecular dynamics simulations were carried out to both define a new computational protocol for the simulation of pseudo-irreversibile AChE covalent inhibitors, and to acquire a better understanding of the structure-activity relationships of the present series of compounds. The results of this computational work prompted us to to evaluate the ability of compounds 5 and 13 to inhibit acetylcholinesterase-induced Abeta aggregation.