Optimization of Flavonoids Extraction from the Roots of Talinnum Paniculatum by Response Surface Methodology and Study on Its Antioxidant Activity

OBJECTIVE To compare in vitro antioxidant activity of flavonoids from the Talinnum paniculatum by different extract methods. METHODS On the basis of the single factors, the effects of liquid-solid ratio, ethanol volume fraction and their interaction on extraction of flavonoids were investigated using Box-behnken design response surface method. The antioxidant activities of three methods used to extract the flavoniods: ultrasonic-assisted, water bath and enzymic methods were compared by the experiments, scavenging capabilities of DPPH·free radical, hydroxyl free radical and superoxide aninoic free radical. RESULTS The optimal extraction conditions were as follows: liquid-solid ratio was 26:1, ethanol volume fraction was 65% and extraction temperature was 70 ℃. Under the above conditions, the extraction yield of flavonoids were 2.620%, which was in accord with the predicted values 2.603%. The total flavonoids of Talinnum paniculatum extracted by the enzymic method had the best antioxidant activity and better antioxidant activity than Vc. CONCLUSION The target of extracting flavonoids compound efficiently from Talinum has been achieved by the optimized technology. The flavonids extracted using different methods has the significantly different antioxidant activity.