Modification of 15-akylidene andrographolide derivatives as alpha-glucosidase inhibitor

15-Alkylidene andrographolide derivatives were specific alpha-glucosidase inhibitors. Semi-synthetic studies of these derivatives led to new alpha-glucosidase inhibitors. Their alpha-glucosidase inhibitory activity was evaluated. Bioactivity results indicated that most of the derivatives were excellent alpha-glucosidase inhibitors. Among them, 6c displayed the best alpha-glucosidase inhibitory bioactivity with an IC(50) value of 8.3 m M.