【作者】 刘亚文；

【导师】 王天翔；

【作者基本信息】 江南大学 ， 化学工艺， 2007， 硕士

【摘要】 本课题主要完成了大豆磷脂的分离提纯、酶水解改性及其改性产物性能测定以及使用大豆磷脂制备维生素C脂质体的研究。采用浓缩大豆磷脂为原料,探索了以乙醇、乙酸乙酯、异丙醇作为溶剂以及使用无机盐沉淀方法提取大豆磷脂主要乳化成分磷脂酰胆碱的工艺条件。最终确定以乙醇作为提取溶剂,提取温度为45(±1)℃,料液比为1:4,提取次数为6次,磷脂酰胆碱在提取物中的百分含量达到45%以上,提取率在80%以上。使用提纯后的产物进行酶水解改性的研究,其最优条件是:反应温度为38(±1)℃、反应时间为7h、酶的用量为100IU/mL、钙离子的浓度为0.025M/L、缓冲液的pH值为8.50、底物浓度为10.0%。在最佳水解反应条件下所测得的酸价为55.03mgKOH/g,水解率在87.6%-94.0%。经硅胶柱层析分离可以得到不同极性的三类磷脂,担体与待分离物的比例为100:1。采用梯度洗脱方式进行分离,洗脱剂的条件是氯仿与甲醇的比例由1:1改变至1:2到1:4,直至用甲醇洗脱。分别得到未知组分磷脂、卵磷脂以及溶血磷脂的浓缩液。未知组分磷脂的高效液相色谱峰面积经归一化计算后达到96.32%,溶血磷脂的含量达到了67.52%。采用R.K.Gupta法测定溶血磷脂的HLB值为9,与水解前的磷脂相比提高50%,乳化稳定性与市售非离子乳化剂乳化效果相似。采用薄膜分散—超声乳化法制备,以包封率为考察指标,经正交优化选择,确定脂质体的最佳配方:卵磷脂/胆固醇/维生素E的摩尔比为4∶2∶0.34;维生素C的浓度为3.3mg/mL;PBS缓冲液的pH值为7.93;成膜时所用氯仿的量为25mL,此时包封率可达58.32%。用扫描电子显微镜观察脂质体的结构,平均粒径为310nm。经脂质体包裹以后,维生素C的稳定性增强。更多还原

【Abstract】 The extracted phosphatidylcholine from soybean phospholipds and modified phosphatidylcholine with phospholipaseA2 .Tested modified products emulsifying properties and reseached on the preparation of vitminC liposome made by soybean phospholipids.Phosphatidylcholine was extracted from soybean phospholipds and alcohol、ethyl actate、isopropanol as optimal sovent and inorganic salt precipitate method respectuvely. The optimal conditions of the extract were: alchohol as extract solvent and its valume was 4 times to the soybean phospholipds weight at 45(±1)℃for 6 times. The phosphatidylcholine concentration could reach above 45% and the yield could reach above 80%.Phosphatidylcholine was modified by phospholipaseA2. The optimal conditions: the temperature was 38(±1)℃,the time of the hydrolysis was 7h, the concentration of PLA2 was 100IU/mL, the concentration of calcium was 0.025mol/mL,the value of tris-HCl buffers wais 8.50. The acidity of the hydrolysis in this situation was 55.03,the rate of hydrolysis was 87.6%-94.0%.Gain the value of Rf of each ingredient by TLC, the Rf value of each ingredient was 0.90,0.56,0.32. Separated the products of the hydrolysis by silica gel columchromatography and used gradient elution for separation. Changed the proportion of chloroform / methanol 1∶1 to 1∶2, and then to 1∶4 ,untill only used the methanol as eluant.The content of lysophospholipid gained 67.52% .Lysophospholipids HLB value sas tested by R.K.Gupta method was 9 and improved 50% than lecithin. The emulsifying stability of lysophospholipids was nearly the same as other emulsifier ,like AEO.To optimize the preparation formulation of vitamin C liposomes. The liposomes were prepared by film dispersion-ultrasonic emulsify method. Taking entrapment efficiency as index, and designing an orthogonal experiment. The optimal formulation were: phosphatidylcholine / cholesterin / vitamin E (molar ratio)4:2:0.34; vitamin C concentration :3.3mg/mL;PBS buffer pH value:7.93;chloroform for film forming :25 mL. Under the formulation the entrapment efficiency was 58.32%. The structure of liposome was observed under the scan electronic microscope. The main diameter of the liposome particles was 310 nm. The stability of vitaminC was improved after entraped by phosphatidylcholine.更多还原