Extraction, Separation And Purification Of Polysaccharides From Astragalu

Astragalus polysaccharide from Radix Astragali is a kind of naturaleffective ingredients with important biological activities. It can improve theimmunity ability and activity of macrophage, restrain the EAS, regulate theconcentration of blood sugar, resist tumour and pathogen and have thefimctions of detoxification.At present, the extraction technology of Astragalus polysaccharide isimmaturity and the extraction efficiency is low. There are many studiesabout the optimum condition of the traditional ethanol extraction in recentyears. Alkali and enzyme is applied in the extraction of Astragaluspolysaccharide at the same time. These methods improve the efficiencycomparatively. We study the extraction technology further and purificationof Astragalus polysaccharide in this test. The main contents of the studyand the results are as following:1. The extraction methods and conditions of astragalus polysaccharidewere studied.The influences of solvent amount, extraction temperature and time ofwater leaching on the yield and purity of astragalus polysaccharide were investigated by orthogonal experiment. The biggest influence factor wastemperature, and then the ratio of material to solvent, the smallest influencefactor was times of extracting. The proper conditions were given: lg ofastragalus was extracted with 5mL water for 4h at 90℃, the yield andpurity of astragalus polysaccharide was 5.31ï¼…, 56.32ï¼…respectively.The processing conditions of extracting crude polysaccharides fromastragalus by using microwave treatment were systematically studied.When the power of microwave was 300w, 1g of astragalus wasmicrowave-assisted extracted with 5mL water for 10min, the yield andpurity of polysaccharide was 3.75ï¼…, 49.22ï¼…respectively. The resultsshowed that microwave auxiliary extraction was able to cut down time ofextraction.The processing conditions of extracting crude polysaccharides fromastragalus by using ultrasonic treatment were systematically studied. Whenthe power of ultrasound was 300w, 1g of astragalus was ultrasound-assistedextracted with 5mL water for 60min at 50℃, the yield and purity ofpolysaccharide was 3.48ï¼…,45.36ï¼…respectively.2. The separation and purification of astragalus polysaccharide werestudied by X-5 macroporous resins.Effective components of astragalus polysaccharide were separatedwith macro porous resin. The adsorption capacity and desorption ratio ofsix adsorption resins including S-8, AB-8, X-5, NKA-9, D4020 and D3520 for separation of astragalus polysaccharide were performed. X-5 wasselected for studying its peculiarity. The X-5 resin fixed bed was selectedfor separation and purification of astragalus polysaccharide. And theadsorption and elution conditions were determined. The results showed thatthe recovery rate of effective components was high and content of effectivecomponents was raised very much by separation and enriched with X-5resin fixed bed. Much impurity was removed. The experiment wassuccessful.3. Composition analysis of astragalus polysaccharides was studied.The TLC method was established to analysis composition of astragaluspolysaccharides. Silica gel plate, n-butanol: HAc: H₂O (9:4:2) asdeveloping solvent, 10ï¼…sulfuric acid-ethanol coloration. Astragaluspolysaccharide was composed of glucose, isodulcitol, arabinose and xylose.