草原苏尼特羊脑中磷脂型DHA萃取 及其结构特性研究Extraction and structural characteristics of phospholipid DHA from grassland Sunite sheep brain

旨在为绿色天然草原羊脑中磷脂型二十二碳六烯酸（DHA-PL）的开发利用提供科学数据，以苏尼特冻干羊脑为原料，采用溶剂萃取其中的粗脂肪，用冰丙酮沉淀得到磷脂，再采用硅胶柱层析法分离其中的磷脂酰胆碱（PC）和磷脂酰丝氨酸（PS）。测定了粗脂肪中胆固醇含量，以及磷脂中PC和PS的含量，分析了粗脂肪、磷脂、PC和PS中DHA含量，以及PC和PS中sn-2位的DHA含量。结果表明：采用体积比2∶ 1乙醇-正己烷萃取冻干苏尼特羊脑中粗脂肪，粗脂肪得率较高，为45%；羊脑粗脂肪中胆固醇含量为29.42 mg/g，粗脂肪的脂肪酸组成中DHA含量为8.89%；磷脂的脂肪酸组成中DHA含量为11.41%；磷脂中PC和PS含量分别为27.67 μg/g和10.69 μg/g，PC和PS的sn-2位脂肪酸组成中DHA含量分别为8.06%和2.59%。综上，可以从苏尼特羊脑中制备易于吸收的DHA-PL。To provide scientific data for the development and utilization of phospholipid docosahexaenoic acid (DHA-PL) in green natural grassland sheep brain, the crude fat was extracted with solvent from the freeze-dried Sunite sheep brain and precipitated with ice acetone to obtain phospholipid, and then the phosphatidylcholine (PC) and phosphatidylserine (PS) were separated by silica gel column chromatography from phospholipid. The total cholesterol content in the crude fat was determined, as well as the PC and PS contents in the phospholipid. The contents of DHA in crude fat, phospholipid, PC and PS, and the contents of DHA at sn-2 position in PC and PS were analyzed. The results showed that the higher crude fat yield of 45% was obtained by extraction with ethanol-n-hexane (volume ratio of 2∶ 1). The cholesterol content in the crude fat was 29.42 mg/g, and the DHA content in the crude fat was 8.89%. The DHA content in the phospholipid was 1141%. The contents of PC and PS in phospholipid were 27.67 μg/g and 10.69 μg/g, respectively. The DHA content in the sn-2 position of PC and PS was 8.06% and 2.59%, respectively. In summary, DHA-PL that is easily absorbed can be prepared from the Sunite sheep brain.