Design, synthesis and biological evaluation of 3,4-dihydro-2(1H)-quinoline-O-alkylamine derivatives as new multipotent cholinesterase/monoamine oxidase inhibitors for the treatment of Alzheimer's disease.

A new family of multitarget molecules able to interact with acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), as well as with monoamino oxidase (MAO) A and B, has been synthesized. Novel 3,4-dihydro-2(1H)-quinoline-O-alkylamine derivatives have been designed using a conjunctive approach that combines the JMC49 and donepezil. The most promising compound TM-33 showed potent and balance inhibitory activities toward ChE and MAO (eeAChE, eqBuChE, hMAO-A and hMAO-B with IC50 values of 0.56μM, 2.3μM, 0.3μM and 1.4μM, respectively) but low selectivity. Both kinetic analysis of AChE inhibition and molecular modeling study suggested that TM-33 binds simultaneously to the catalytic active site and peripheral anionic site of AChE. Furthermore, our investigation proved that TM-33 could cross the blood-brain barrier (BBB) in vitro, and abided by Lipinski's rule of five. The results suggest that compound TM-33, an interesting multi-targeted active molecule, offers an attractive starting point for further lead optimization in the drug-discovery process against Alzheimer's disease.