Abstract: The purification process of total saponins from Ornithogalum caudatum and their antioxidant activity were studied.The adsorption and desorption rates of total saponins were selected as evaluation indexes,the types of macroreticular resin was screened and the purification parameters were further optimized.The results showed that AB-8 macroporous resin was considered to have favorable adsorption and desorption rates on total saponins of O.caudatum (OCTS).The optimal purification conditions were as follows:the ratio of O.caudatum dosage to the amount of macroporous resin did not exceed 7:1;distilled water and 30% ethanol were used to clean the impurity,and 70% ethanol was selected to elute total saponin.Under these conditions,the purity of OCTS obtained was 55.18%.Then,the antioxidant activity of purified OCTS was studied.The IC₅₀ of OCTS on hydroxyl radical,superoxide anion radical and DPPH radical were 2.43,2.28 and 0.05 mg/mL,respectively.It suggested that OCTS had good antioxidant activity.

Key words: Ornithogalum caudatum, total saponins, macroreticular resin, purification, antioxidant activity