Abstract:Response surface methodology was used to optimize the compound enzyme-assisted ultrasonic extraction of gypenosides from Gynostemma pentaphyllum and to investigate their in vitro antioxidant and hypoglycemic activities. The experimental results showed that the optimal extraction conditions for gypenosides were as follows： a compound enzyme ratio （pectinase∶cellulase） of 2∶1 （U/U）， a compound enzyme dosage of 192 U/g substrate， an enzymatic hydrolysis-ultrasonic time of 60 min， a temperature of 63 ℃， an ultrasonic power of 360 W， an ethanol concentration of 70%， and a liquid-to-material ratio of 55∶1 （mL/g）. Under these conditions， the extraction yield of gypenosides was 9.83%. The half-maximal inhibitory concentration （IC50）values of the gypenoside extracts for scavenging DPPH and ABTS+ radicals were 636.14 and 384.05 μg/mL，respectively， and the IC50 value for inhibition of α-glucosidase activity was 451.98 μg/mL， indicating that gypenosides possess certain in vitro antioxidant and hypoglycemic activities and have good potential for development and application.