Chalcone flavokawain A (1) and chalcone prenyl ether derivative 2 were synthesized from naringin, through glycoside hydrolysis, O-methylation or O-prenylation, and base-catalyzed ring-opening reaction. Based on Mannich reaction of chalcone 1 and chalcone prenyl ether derivative 2, fourteen new chalcone Mannich base derivatives 3～16 were synthesized. The aminomethylation occurred preferentially at 3'-C position of chalcones. The structures of all synthesized compounds were determined by MS, NMR and IR spectra. All the synthetic compounds were evaluated for acetylcholinesterase (AChE) inhibitory activity. The results show that chalcone mannich base derivatives 3～5, 9 exhibit good AChE inhibitory activity.

Key words: chalcone, flavokawain A, Mannich base, synthesis, acetylcholinesterases inhibitory activity