Structure-Activity Relationships of N-Cinnamoyl and Hydroxycinnamoyl Amides on α-Glucosidase Inhibition

Currently, there is an increasing interest towards α-glucosidase inhibition of various diseases including diabetes mellitus type 2, cancer, HIV, and B- and C-type viral hepatitis. Cinnamic acid derivatives have been shown to be potentially valuable as a new group of α-glucosidase inhibitors. Therefore, herein, the α-glucosidase inhibitory activity of trans-N-cinnamoyl and hydroxycinnamoyl amides was studied in vitro. Results revealed that the tested hydroxycinnamoyl amides (1–16) inhibited a-glucosidase with IC50s ranging between 0.76 and 355.1 μg/ml. Compounds 1, 2, 5, 6, 9, 14, and 15 showed significant inhibition of yeast α-glucosidase, being even more potent ones than the used positive inhibitor acarbose (IC50=2.50±0.21 μg/ml)