Study On Separation And Purification Of Glycoprotein From Chinese Yam

Glycoprotein is a compound protein that is composed of oligosaccharides and polypeptide or protein combined through the covalent band. Research has revealed its many biological functions, such as adjusting immunity, inhibiting tumour, reducing blood sugar and blood fat, preventing oxidation and caducity. As a result, it has an extensive prospect in promoting people's health level. In this dissertation, the microwave assisted extraction of glycoprotein from Chinese yam, the water extraction of glycoprotein from Chinese yam, its purification, relative molecular mass determination and antioxygenic activity were investigated, the main conclusions are as follow:1. The three factors—microwave power, extracting time, water-material ratio in the microwave assisted extraction were picked out for orthogonal experiment. The results of analysis are as follows:①Analysis of range manifested that the optimum extracting condition was microwave power 200 W, extracting time 1 minute, water-material ratio 10 milliliter per gram.②Variance analysis manifested that the major factor which had distinguished influence on yield was microwave power, then the other factors were extracting time and water-material ratio.③The optimum extracting condition was authenticated and the yield of glycoprotein was 1.871%.2. The three factors—water temperature, time of water extraction, water-material ratio in the water extraction were singled out for orthogonal experiment. The consequences of analysis are as follows:①Analysis of range indicated that the optimum extracting condition was water temperature 40℃, time of water extraction 2 hours, water-material ratio 10 milliliter per gram.②Variance analysis indicated that the principal factor which had outstanding influence on yield was water temperature, in proper order, the other factors were water-material ratio and time of water extraction.③The optimum extracting condition was proved and the yield of glycoprotein was 1.007%.3. The glycoprotein of Henan Chinese yam was purified with DEAE-52 and Sephadex G-75. As a result, two portions of glycoprotein, GLP-Ⅰand GLP-Ⅱ, were collected respectively. Experiment of sodium dodecyl sulphate-polyacry-lamide gel electrophoresis (SDS-PAGE) identified their purity and measured their relative molecular mass. The result indicated that GLP-Ⅰand GLP-Ⅱboth achieved electrophoretic pure. The relative molecular mass of GLP-Ⅰand GLP-Ⅱwere 13000 Da and 38000 Da.4. The glycoprotein of Jiangsu Chinese yam was purified with DEAE-52 and Sephadex G-75. As a result, one fraction of glycoprotein was assembled. Experiment of SDS-PAGE appraised its purity and measured its relative molecular mass. The result showed that the glycoprotein chalked up electrophoretic pure. The relative molecular mass of the glycoprotein was 35200 Da.5. By measuring hydroxy radical clearance rate and the like of SOD activity, the influence of glycoprotein separated from Chinese yam water-soluble extracts, on the antioxygenic activity was researched. The result indicated that the glycoprotein of Chinese yam had the effect of clearing hydroxy radical and enhancing the like of SOD activity. Therefore, the glycoprotein from Chinese yam had a certain capacity of antioxidation.