4-Hydroxycinnamamide

(E)-p-Coumaramide is an α-Glucosidase inhibitor that can be isolated from Welsh onion[1].

[1] Nishioka T, et al. Isolation and activity of N-p-coumaroyltyramine, an α-glucosidase inhibitor in welsh onion (Allium fistulosum)[J]. Bioscience, biotechnology, and biochemistry, 1997, 61(7): 1138-1141.