|
|
【答案】应助回帖
dong5705(金币+50, 翻译EPI+1): 谢谢 2011-04-28 22:06:48
Abstract
Purpose: Prepare tremella polysaccharide of different molecule weight, investigate their physiochemical and structural properties and screen polysaccharide of optimum activity which decreases toxicity of antitumor drugs and promotes function of leukocytes.
Method: Extraction technology was obtained through orthogonal experiment of tremella polysaccharide. Tremella polysaccharides of different molecular weight were prepared by acid hydrolysis, physiochemical properties of which were investigated through phenol sulfuric acid method, m-hydroxydiphenyl method, Lorry method and BCA method. Saccharide component was determined through HPLC, and methylation and GC-MS were used to confirm glycosidic bond pattern of neutral monosaccharides. Conduct intravenous injection of normal mice and tumor-bearing mice, and observe toxicity reducing ability of tremella polysaccharide with different molecular weights and branch types on antitumor drugs.
Result: Optimum extraction technology drawn from orthogonal experiment is described below. Boil samples with 50 times of water for 3 times, and each time for 3 hrs. Tremella polysaccharides of 200,000 Dalton, 30,000 Dalton and 4,000 Dalton were prepared through acid hydrolysis. Physiochemical properties were determined. Molecule of 200,0000 Dalton contains 76.5% of neutral saccharides, 19.8% of acid saccharides and 9% of proteins. Molecule of 30,000 Dalton contains 78.2% of neutral saccharides 22.1% of acid saccharides and 6.2% of proteins. Molecule of 4,000 Dalton contains 83.1% of neutral saccharides 22.3% of acid saccharides and 8.2% of proteins. HPLC analysis shows, the above mentioned three molecules are composed of Man, Glu, Xyl, as well as small amount of 1→4 linked Xyl. It can be concluded from structure-activity analysis and pharmacological actions of tremella polysaccharide that molecule of 30,000 Dalton promotes leukocytes better when treating antitumor drugs caused decrease of peripheral blood leukocytes.
Conclusion: This experiment investigates isolation, physiochemical properties, structure-activity relationship, and pharmacology of tremella polysaccharide. Sugar fractions of tremella polysaccharide which decreases toxicity of antitumor drugs and promotes leukocyte, were screened. Structure-activity relationship and function mechanism of tremella polysaccharide were summarized, which is of importance to drug development.
Key words: tremella polysaccharide, physiochemical properties, PMP derivation, HPLC analysis, GC-MS |
|
回复此楼