Study On Extraction And Purification Of Glycoprotein From Pumpkin

Glycoprotein is a kind of combinative protein that is composed of polysaccharide and protein through the covalent bond. It has many functions such as improving immunity, inhibiting tumour, reducing blood sugar and preventing oxidation and caducity, thus it has research value and can be made into new type medicine. In this paper, the extraction, separation, purification and structure analysis of glycoprotein from pumpkin powder were studied, the main conclusions are as follow:1. The extraction and separation of glycoprotein from pumpkin powder were studied by the method of extracting polysaccharide. Extraction with water and deposition with ethanol of polysaccharide from pumpkin powder was studied. The optimum conditions for the yield of polysaccharide were temperature 45℃, ethanol concentration 70%, water 1:16 and time 30 min. The recovery and purity of impure polysaccharide were 6.63% and 81.91% respectively in the conditions. The recovery of glycoprotein was 1.38% from impure polysaccharide through ethanol grading deposition and SephadexG-75 chromatography.2.The extraction and separation of glycoprotein from pumpkin powder were studied by the method of extracting protein. Extraction with alkali and deposition with acid of protein from pumpkin powder was studied. The optimum conditions for the yield of protein were temperature 60℃, pH 8.5, water 1:16 and time 30 min. The recovery and purity of impure protein were 6.82 % and 81.27% respectively in the conditions. The recovery of glycoprotein was 0.89% from impure protein through vitriolic ammonium grading deposition and SephadexG-75 chromatography.3. By comparing different extraction methods for glycoprotein, the extraction with water and deposition with ethanol was preferable4. The simple structural analysis for glycoprotein of pumpkin powder was studied. The glycoprotein was proved to be homogeneous by paper chromatography, SephadexG-75 chromatography and electrophoresis. Its molecular weight was estimated to be 30000 approximately. Its carbohydrate content was 78.06% and protein content was 13.74%. The existence of o-glycoside linkage was showed byμv analysis of the glycoprotein.