A series of novel flavonolignans were synthesized by the reaction between a lignan named samin (1) and a range of flavonoids. This simple and rapid approach allowed direct assembly of these two bulky motifs in good yields without the formation of byproducts. Upon evaluation of antidiabetic activity of the synthesized products, epicatechinosamin (β-2g) was the most active α-glucosidase inhibitor toward maltase and sucrase. The kinetic study indicated that β-2 g inhibited the enzymes in a mixed manner of competitive and noncompetitive inhibition.
Keywords: Flavonolignan; Friedel-Crafts; antioxidant; diabetes; glucosidase; oxocarbenium.