Abstract:Deep eutectic solvents（DESs）coupled with ultrasound-assisted extraction（UAE）was employed to extract physalin from the calyx of Physali alkekengi L.and the sugar-lowering activity of the extracted physalin was analyzed.Five different DESs were used for extraction and their performance was evaluated.On the basis of single factor tests，the response surface methodology was employed to optimize the extraction conditions of physalin from the calyx of P.alkekengi.The sugar-lowering activity of the extracted physalin was analyzed based on the inhibitory effects on α-glucosidase and α-amylase.The results showed that DESs（choline chloride ∶glucose=2 ∶1）exhibited the highest extraction yield，which was significantly higher than that with 75% ethanol as the solvent.The conditions for physalin extraction were optimized as follows：solid-to-liquid ratio of 1∶10（g/mL），ultrasonic power of 320 W，ultrasonic time of 30 min，and water content of 15%.Under these conditions，the yield of physalin extracted from the calyx of P.alkekengi was（8.96±0.15）mg/g.The physalin extracted from P.alkekengi had sugar-lowering activity.