Synthesis and anticholinesterase inhibitory activity of Mannich base derivatives of flavonoids

Hesperidin-derived 2'-hydroxy-3,4,4',6'-tetramethoxy-chalcone and 5-hydroxy-7,3',4'-trimethoxy-flavone underwent reaction with formaldehyde and a series of secondary amines producing 11 new Mannich base derivatives of flavonoids. The aminomethylation occurred preferentially at the C-3' position of the chalcone and at the C-6 position of flavone. These aminated derivatives of flavonoids were evaluated as inhibitors of acetylcholinesterase (AChE) and the results showed that two of them exhibited excellent AChE inhibitory activity.