Study on the Techniques for Comprehensive Utilization of Saponins,Flavonoids and Polysaccharides in Astragalus

[Objective] The study aimed to explore the technologic conditions for getting saponins,flavonoids and polysaccharids in Astragalus at the same time.[Method] According to the difference on solubility of 3 kinds of effective components,the saponins and flavonoids in Astragalus were firstly extracted by the method of circumfluence with ethanol as solvent and the residue of ethanol-extraction was then used to extract polysacchrides by distilled water.The flavonoids and saponins in ethanol extracting fluid were isolated and purified by anion-exchange resin D280.[Result] The optimum conditions for extracting saponins from Astragalus were as following: with 70% ethanol as sovent,liquid-solid ratio of 7∶1,extracting 3 times at 78 ℃ and 100 min for each time;The optimum conditions for extracting flavonoids from Astragalus were as following: with 80% ethanol as sovent,liquid-solid ratio of 7∶1,extracting 4 times at 78 ℃ and 80 min for each time;The optimum conditions for extracting polysaccharides from Astragalus were as following: distilled water as solvent,liquid-solid ratio of 16∶1,extracting 3 time at 100 ℃ and 2 h each time.The optimum conditions for separating saponins and flavonoids by D280 anion-exchange resin were as following: the ethanol extracting fluid was concentrated and loaded onto the chromatography column of after adjusting pH value to 8.0.The saponins were obtained by collecting outflow and leaching fluid of 0.1%NaOH;The flavonoids were obtained by eluting the column with 80% ethanol and 80% ethanol containing 10%NaOH sequentially.[Conclusion] The saponins,flavonoids and polysaccharids in astragalus could be extracted and isolated in the same process flow by using combined techniques mentioned above and the effective components in astragalus could be used compressively.