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

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).