Studies on Inhibitory Activities of Fukiic Acid Esters on Germination, α-Amylase and Carboxypeptidase A

Fukinolic acid (1) and cimicifugic acid A (2), caffeic acid analogs, as well as rosmarinic acid (3) and caffeic acid (4) showed inhibition on seed germination and seeding growth. The potency of 1 and 2 was comparable with that of 3. Compounds 1 and 2 also showed strong inhibitory activites as well as 3 and 4 on α-amylase. The activity of 1 was higher than that of acarbose used as a positive control, and its 50% inhibitory concentration (IC50) was 2.41×10-5 M. Compounds 1 and 2 also showed inhibitory activities strong as 3 and stronger than 4 on carboxypeptidase A. The activities of 1 and 2 were higher than that of 1, 10-phenanthroline used as a positive control.