Abstract：The aim of this study was to optimize the extraction process of total flavonoids from Annona squamosa leaves and study their antioxidant activity in vitro. Using ethanol as extraction solvent, the response surface methodology was used to optimize the extraction process of total flavonoids from lychee leaves based on the results of single factor experiments. DPPH,-OH and ABTS were used as indicators to comprehensively evaluate the in vitro antioxidant activity of total flavonoids from lychee leaves. The results showed that the optimal extraction parameters were: Ethanol volume fraction 70%, liquid to material ratio 50∶1(mL: g), ultrasonic time 85 minutes, ultrasonic temperature 67 ℃. The extraction rate of total flavonoids was 4.37% under this process. The antioxidant activity of total flavonoids was evaluated by three indexes(the scavenging ability of DPPH,-OH and ABTS). The results showed that total flavonoids from Annona squamosa leaves had good scavenging effects on DPPH,-OH and ABTS, with the IC50 values were 94.78 μg/mL, 756.34 μg/mL and 419.91 μg/mL, respectively. And the scavenging effect on -OH was stronger than that of VC. The process determined in this study was simple and feasible. The total flavonoids extracted from Annona squamosa leaves had high extraction rate and strong antioxidant capacity.
2024, Vol. 37 
