Compounds of isolated from roots extract of Pueraria thunbergiana were tested their inhibitory effects on α-glucosidase and α-amylase. Inhibitory activity of methylene chloride (MC) fraction and ethyl acetate (EA) fraction against α-glucosidase showed more than 60% at a concentration of 500μg/ml. Among the nine compounds tested on α-glucosidase, biochanin A, (-)-tuberosin and calycosin from MC fraction and daidzein from EA fraction were stronger inhibitors than acarbose (IC50=530μg/ml), and their IC50 were 9, 144, 328 and 20μg/ml, respectively. Biochanin A and (-)-tuberosin also inhibited α-amylase activity as like as acarbose IC50=20.5μg/ml), and their IC50 were 22 and 348μg/ml, respectively. Although daidzein was already known α-glucosidase inhibitory effects, it was newly evaluated that biochanin A and (-)-tuberosin inhibited α-glucosidase as well as α-amylase, and that calycosin did α-glucosidase.

This study was carried out to screen high α-glucosidase inhibitor (AGI) activity pepper lines from EMS treated mutants of pepper. The optimal concentration of EMS for inducing mutants to pepper was 0.15M and the optimal treatment time of EMS was 2 hours. With this condition, many mutants which have high AGI activity were screened and especially leaf of two lines were showed 27 times inhibitory activity on α-glucosidase comparing with control. There is no difference between mutants and nornmal plant in growth. These results indicated that AGI activity of pepper leaf would be increased by mutation.