Cholinesterase inhibitors:: Xanthostigmine derivatives blocking the acetylcholinesterase-induced β-amyloid aggregation

In continuing research that led us to identify a now class of carbamate derivatives acting as potent (Rampa et al. J. Med. Chem. 1998, 41, 3976) and long-lasting (Rampa et al. J. Med. Chem. 2001, 44, 3810) acetylcholinesterase (AChE) inhibitors, we obtained sonic analogues able to simultaneously block both the catalytic and the beta-amyloid (A beta) proaggregatory activities of AChE. The key feature of these derivatives is a 2-arylidenebenzocycloalkanone moiety that provides the ability to bind at the AChE peripheral site responsible for promoting the A beta aggregation. The new carbamates were tested in vitro for the inhibition of both cholinesterases and also for the ability to prevent the AChE-induced All aggregation. All of the compounds had AChE IC50 values in the nanomolar range and showed the ability to block the AChE-induced A beta aggregation, thus supporting the feasibility of this new strategy in the search of compounds for the treatment of Alzheimer's disease.