Objective: To study the inhibitory effects of Gardeniae Fructus extracts on alpha-glucosidase activity. Method: The inhibitory activities of each extracted parts of Gardenia jasminoides against alpha-glucosidase were tested by the colorimetry of PNPG

the reaction system of which included 67 mmol·L-1 potassium phosphate buffer 870 μL

1 g·L-1 glutathione solution 25 μL

2.74 U·mL-1 α-glucosidase solution 35 μL

15 mmol·L-1 PNPG solution 70 μL

0.1 mol·L-1 Na2CO3 solution 4 mL. Result: At concentrations of 50

100 g·L-1

Gardeniae Fructus total extract

iridoids and gardenia yellow reduced significantly the activities of alpha-glucosidase with inhibitory rates of 61.47%

83.20%; 34.27%

55.73%; 78.13%

96.93%. Conclusion: Gardeniae Fructus extracts have the inhibitory effects on alpha-glucosidase

and the active position is probably Iridoids and Gardenia yellow.