積雪草多糖的提取及其抗氧化性能研究

生物工程論文編號:SW047  論文字數:8788,頁數:23

目 錄
中文摘要 I
英文摘要 II
目 錄 III
1 緒 論 1
1.1 積雪草概述 1
1.2 積雪草研究現狀 1
1.3 多糖概述 2
1.4 多糖研究現狀 2
1.5 本章小結 3
2 實驗部分 4
2.1 材料與設備 4
2.2 實驗主要試劑 5
2.3 實驗方法 6
2.4 本章小結 9
3 結果和討論 10
3.1 積雪草粗多糖提取 10
3.2 粗糖蛋白中蛋白質含量的測定 10
3.3 脫蛋白處理 11
3.4 脫蛋白效果復測 11
3.5 粗多糖中己糖含量的測定 11
3.6  β-胡蘿卜素漂白法測定積雪草多糖抗脂質過氧化活性 13
3.7  單糖組成分析 13
4 總結與展望 16
致 謝 17
參考文獻 18

摘要： 本實驗以積雪草為原料，用水煮醇沉法提取了積雪草粗糖蛋白，測得其提取率為6.5%；用考馬斯亮藍G-250法對提取的積雪草粗糖蛋白的蛋白質含量作了測定，結果為3.45%；得到的粗糖蛋白用酶+Sevag法脫蛋白，處理了8次后無明顯的蛋白層；考馬斯亮藍G-250法復測脫蛋白后的積雪草多糖，測得所剩蛋白含量極微，說明脫蛋白效果顯著；脫蛋白后得到的積雪草多糖用苯酚-硫酸法測糖含量，測得粗多糖中己糖含量為57.9%。
 采用β-胡蘿卜素漂白法測定積雪草多糖抗脂質過氧化活性，結果顯示積雪草多糖在劑量為10~20 mg/ml范圍時，具有較強的抗氧化活性。在同等劑量5 mg/ml下強于陽性對照Vc，5 mg/ml的積雪草多糖的抑制率為54.3%，而陽性對照Vc(5 mg/ml)的抑制率為38 %。
    對積雪草粗多糖的單糖組成進行了氣相色譜檢測，結果顯示其單糖組分中含有麥芽糖和D-木糖。
關鍵詞：積雪草；多糖；提�。豢寡趸�活性

Study on the extraction, purification and antioxidant activity of polysaccharide in Centella asiatica
Abstract: In this study, the Centella asiatica was extracted with water and Centella asiatica crude polysaccharide protein was obtained with a productivity of 6.5%. The protein content of the Centella asiatica crude polysaccharide measured with Coomassie brilliant blue G-250 method was 3.45%. The crude polysaccharide was deproteined with enzyme and Sevag, after handling 8 times there was no obvious protein layer left. Took the Coomassie brilliant blue G-250 method again , and result showed that there was little protein contained in the crude polysaccharide, the effect of deproteinning was good. The polysaccharide content of the deproteined crude polysaccharide was measured with phenol and sulfuric acid, hexose had a content of 57.9%.
   The antioxidant activity of crude polysaccharides was also studied by β-carotene bleaching assay, which showed that Centella asiatica crude polysaccharides have distinct antioxidant capacity compared with vitamin C as the positive control.
    We us the GC method to test the monosaccharide composition of Centella asiatica polysaccharides, and the result showed that maltose and D-xylose are two compositions of crude polysaccharides.
Key Words：Centella asiatica; Polysaccharides; Extraction; Antioxidant activity