Study On Extraction, Purification And Activity Of Polysaccharide In Gastrodia Elata Blume

Gastrodia elata Blume is a saprophyte widespread in Chinese province Shanxi, Yunnan, Guizhou, Sichuan, etc. This drug is considered to have very beneficial properties. In clinical practice, this plant is used to treat vertigo, blackout, headache, hemiplegia, neuralgia, paralysis, lumbago, hypertension, coronary heart disease and it also has sedative actions. At present, the research of Gastrodia elata Blume is merely limit to Gastrodin. There is no systemic report on the research of Gastrodia elata Blume Polysaccharide. The objective of this paper is to lay a foundation for utilization and exploitation of Gastrodia elata Bl.ume polysaccharide.In order to study the polysaccharide of Gastrodia elata Blume, Gastrodia elata Blume was taken as material. The research contains extraction, ultrasonic extraction and purification, chemical and physical properties and composition of monosaccharide of Gastrodia elata Blume polysaccharide, Gastrodia elata Blume polysaccharide of antioxidation and anti-bacterial activity. The major results were shown as follows:1. The quantifying of Gastrodia elata Blume polysaccharide was used by the anthrone-sulfuric acid method, and determined the polysaccharide's content.2. Gastrodia elata Blume polysaccharide was obtained by using hot water extraction and ultrasonic wave extraction. On the basis of one-factor tests, the method of response surface analysis was carried out to determine the optimal condition of the extraction. The using hot water extraction optimal condition were: extraction 36min at 58℃with 1:37 ratio of Gastrodia elata Blume to water. Under the optimized condition, the extraction rate of Gastrodia elata Blume Polysaccharide was 9.25%.The ultrasonic wave extraction optimal condition were:ultrasonic extraction temperature 66℃, time 34min and the ratio of Gastrodia elata Blume to water was 1:45. Under the optimized condition, the extraction rate of Gastrodia elata Blume Polysaccharide was 32.78%.The yield and content of polysaccharide by using ultrasonic wave extraction were higher than using hot water. The method of ultrasonic wave was optimum to extract polysaccharide. 3. The purification of Gastrodia elata Blume polysaccharide. The successive procedures were as follows: first,G-40 was precipitated with 0%~40%(v/v) ethanol,G-80 was precipitated with 40%~80%(v/v) ethanol,secondly, G-40 and G-80 were deproteinized by enzyme combined with Sevag method and dialysised with distilled water, thirdly, GeB40-1 and GeB80-4 was further purified by DEAE-52 cellulose column chromatography and collected according to the peak of the elution curve of water. The UV spectrum's result indicated this polysaccharide component does not contain protein and other impurities.4. The physical and chemical properties of Polysaccharide GeB40-1:white powder; diss- olves in water;doesn't dissolve in some organic solvent such as ethanol,aether and acetone; doesn't contain Starch,reducing sugar,protein and nucleic acid;the data of IR revealed that GeB40-1 is chiefly linked byα-glycosidic bonds;the average molecular weight is more than 8000 Dalton;the specific rotation is +150.5°; the melting point is 270.3-271.1℃. Ion Chroma- tography analyze monosaccharide composition of polysaccharide:GeB40-1 is composed of L-rhamnose,D-galactose,D-glucose,D-xylose and D-mannose with the molar ratio of 29:1:42: 11:2.5. The physical and chemical properties of Polysaccharide GeB80-4: yellow powder; dis- solves in water;doesn't dissolve in some organic solvent such as ethanol,aether and acetone; doesn't contain Starch,reducing sugar,protein and nucleic acid;the data of IR revealed that GeB80-4 is chiefly linked byα-glycosidic bonds;the average molecular weight is more than 8000 Dalton;the specific rotation is -94.7°; the melting point is 278.5-279.9℃. Ion Chromato- graphy analyze monosaccharide composition of polysaccharide:GeB80-4 is composed of L-rhamnose,D-galactose and D-glucose with the molar ratio of 2.5:1:25.6. The antioxidative activity of Gastrodia elata Blume polysaccharide:GeB40 and GeB80 had the ability of scavenging oxygen free radicals,hydroxyl free radical,DPPH·radical and reducing ability. Oxygen free radicals scavenging ability of GeB40 was higher than GeB80; Hydroxyl free radical,DPPH·radical scavenging ability and reducing ability of GeB80 were higher than GeB40.7. The antibacterial activity of GeB40,GeB80 and ethanol extracts from Gastrodia elata Blume were shown as follows: GeB40,GeB80 and ethanol extracts from Gastrodia elata Blume had Bacterial Inhibition and Fungal Inhibition. GeB40 had strong inhibitory effect on Escherichia coli and Rhizopussp. GeB80 had strong inhibitory effect on Rhizopussp., Penicilliumsp. and Staphylococcus. aureus. GeB80 had strong inhibitory effect on Rhizopussp.,Penicilliumsp. and Staphylococcus. aureus. Ethanol extracts had strong inhibitory effect on Staphylococcus. aureus,Escherichia coli and Penicilliumsp. GeB80 had stronger inhibitory effect than GeB40,and Ethanol extracts was stronger than GeB80 and GeB40. 8. The detecting method in vitro of ACE inhibition ratio was adopted on the study of Gastrodia elata Blume polysaccharide's antihypertensive activity. The test result indicate: GeB40 and GeB80 had good antihypertensive activity, GeB80 stronger than GeB40. When the Concentration of GeB40 and GeB80 was 10 mg·mL-1, ACE inhibition ratio of their were over 50 %.The innovation points were as follows:1. The Gastrodia elata Blume polysaccharide optimum parameter was obtained by using hot water extraction and ultrasonic wave extraction,separation and purification including deproteinization, dialysised and column chromatographic.2. The studies of Gastrodia elata Blume polysaccharide involved monosaccharide composition and antihypertensive activity.