Synthesis and biological evaluation of tacrine-thiadiazolidinone hybrids as dual acetyl-cholinesterase inhibitors

The synthesis of tacrine-thiadiazolidinone hybrids is described. These compounds are designed as dual acetylcholinesterase inhibitors binding simultaneously to the peripheral and catalytic sites of the enzyme. All tested compounds exhibit significant AChE inhibitory activity. Competition assays using propidium as reference of selective ligand for the peripheral anionic site on acetyleholinesterase indicates the influence of the designed compounds over the peripheral site. They can be considered as new leads in the optimization of Alzheimer's disease modifying agents.