Synthesis and biological evaluation of novel 8-aminomethylated oroxylin A analogues as α-glucosidase inhibitors

A series of 8-aminomethylated derivatives of oroxylin A were prepared by Mannich reaction and their α-glucosidase inhibition activities were studied. A series of 8-aminomethylated derivatives ( 1a– 1j) were prepared by Mannich reaction of oroxylin A ( 1) with appropriate primary or secondary amines and para-formaldehyde. All the compounds were tested for their α-glucosidase inhibition activity against both yeast and rat intestinal α-glucosidase. Some of the compounds demonstrated significantly better α-glucosidase inhibitory activity than the parent compound (oroxylin A).