Abstract: The objection was to find out the optimal extraction conditions of flavonoids from Lilium lancifolium Thunb (LLF) and evaluate its antioxidant activity.Based on the single factor experiments,Box-Behnken Design of response surface methodology was appled to optimize the extraction process with the flavonoids yield as evaluation index.The optimal extraction conditions were as follows:ethanol concentration 66%,extraction time 99 min,extraction temperature 80 ℃,ratio of liquid to material 44 mL/g,respectively.Under aforementioned conditions,the experimental flavonoids yield was 2.28±0.06 mg/g,close to the predicted value (2.29 mg/g).Furthermore,LLF showed significant antioxidant activity against DPPH,superoxide and hydroxyl radical and iron-chelating ability.The scavenging/chelating rate were respectively up to 89.55%、45.69%、84.20% and 84.32%.In general,the process is a very effective method to extract LLF and the LLF possesses strong antioxidant capacity in vitro.

Key words: Lilium lancifolium Thunb, flavonoids, response surface methodology, antioxidant activity