Abstract: The extraction conditions of isofaxidin from Eleutherococcus senticosus were optimized by using the spherical symmetrical design test and single factor experiments.The optimized extraction conditions were as follows:concentration of sulfuric acid,solid-liquid ratio,concentration of ethanol,extraction time were 11.5%,1:8,50% (v/v) and 30 min,respectively.With the optimal extraction conditions,the yield of isofaxidin from E.senticosus was 29.5 μg/g.Besides,the antioxidant activity and antitumor activity of the extract were studied.The results showed isofaxidin exhibited good inhibition activity of lipid peroxidation.Inhibition rate of 1 mg/mL isofaxidin was 23.15%,the same as 0.2 mg/mL of vitamin C.In addition,isofaxidin exhibited radical scavenging activity against superoxide in a dose-dependent manner.Isofaxidin also exhibited good in vivo and in vitro antitumor activities.

Key words: Eleutherococcus senticosus, isofaxidin, response surface, antioxidant activity, antitumor activity