Homobivalent quinazolinimines as novel nanomolar inhibitors of cholinesterases with dirigible selectivity toward butyrylcholinesterase

Homobivalent dimers of quinazolinimines, which bridge the imine nitrogen atoms via a hepta-and an octamethylene spacer, with different ring sizes of the alicycles were synthesized from the corresponding quinazolinethiones. The resulting compounds show > 100-fold increase of inhibitory activities compared to related monomeric compounds yielding low-nanomolar inhibitors. For heptamethylene dimers, mixed inhibition profiles were obtained, whereas for the octamethylene compounds selectivity toward butyrylcholinesterase (> 180) can be achieved with an eight-membered alicycle.