本文選題：磷脂酰膽堿　切入點：甘油磷酸膽堿　出處：《合肥工業(yè)大學》2017年碩士論文　論文類型：學位論文

【摘要】：磷脂酰膽堿(PC)及其水解產物L-α-甘油磷酸膽堿(GPC)廣泛應用于醫(yī)藥和保健品領域。以磷脂酰膽堿為基礎的生物轉化產物在醫(yī)藥、食品、化妝等行業(yè)有重要用途。本文以富含磷脂酰膽堿的大豆卵磷脂為底物,以磷脂酶催化為例,研究了卵磷脂懸浮液酶催化水解前后的表面化學性質的變化規(guī)律及其催化制備甘油磷酸膽堿的工藝,為磷脂酰膽堿的生物轉化提供了新的催化體系。論文首先將大豆卵磷脂高速均質為水相的卵磷脂懸浮液,對卵磷脂在水相中的表面化學性質進行了研究。結果表明:當緩沖液pH增加時,顆粒粒徑變大,體系的電導率增大,Zeta電勢絕對值降低,體系的粘度下降;磷脂酶為生物催化劑催化卵磷脂懸浮液時,卵磷脂懸浮液的Zeta電位出現波動,pH出現略微下降后最終保持在4.70左右,電導率略微上升后保持在9.50mS/cm左右,流體粘度因固含量下降而下降,最終會保持平衡。其次以卵磷脂懸浮液表面化學性質研究結果為基礎,構建了大豆卵磷脂的酶法催化制備甘油磷酸膽堿的水相反應體系,并對其催化條件進行了研究。實驗結果得到:初始底物濃度為20.0%,反應溫度為55℃,初始pH為5.0,酶用量為87.03U/g,當反應進行到第90min時,體系的底物終濃度由20.0%降低至6.5%,此時,加入濃度為25.0%的底物,使得體系的終濃度由6.5%上升至13.0%,繼續(xù)反應6h,反應的PC轉化率達到90%左右。補料調節(jié)底物濃度的方式有利于酶催化反應的進行。論文最后研究了水相酶催化反應后的產物分離純化工藝,該工藝先通過萃取的方法除去脂溶性雜質,萃取時二氯甲烷用量為反應液體積的0.4倍,甲醇的用量為0.5倍。產物經過堿化后再進行脫色。之后,使用溶劑除鹽法去除部分乙酸鈉,使用的溶劑為無水乙醇,溶解溫度為55oC。最后,產物需要通過硅膠柱層析精制,其流動相為9:1的甲醇和30%氨水混合液。本文通過對磷脂酰膽堿水相催化體系的關鍵特性研究,確定了磷脂酶水相催化體系的pH、粘度、底物含量等參數,并在此體系中制備得到了 GPC產品,研究結果為綠色環(huán)保的磷脂酰膽堿生物轉化技術提供理論依據。
[Abstract]:Phosphatidylcholine (PCP) and its hydrolysate L- 偽 -glycerophosphatidylcholine (L- 偽 -glycerophosphate choline) are widely used in the field of medicine and health care products. The biotransformation products based on phosphatidylcholine are used in medicine, food, In this paper, soybean lecithin rich in phosphatidylcholine is used as substrate and phospholipase catalysis as an example. The changes of surface chemical properties of lecithin suspension before and after catalytic hydrolysis and the preparation of glycerophosphate choline were studied. It provides a new catalytic system for the biotransformation of phosphatidylcholine. Firstly, soybean lecithin was homogenized into aqueous phosphatidylcholine suspension at high speed. The surface chemical properties of lecithin in aqueous phase were studied. The results showed that the particle size increased with the increase of buffer pH and the absolute value of Zeta potential decreased and the viscosity of the system decreased. When phospholipase was used as a biocatalyst to catalyze lecithin suspension, the Zeta potential of lecithin suspension fluctuated slightly and the pH value decreased slightly, and finally remained around 4.70, and the electrical conductivity increased slightly and remained at 9.50mS / cm or so. The viscosity of the fluid decreases because of the decrease of solid content, which will eventually maintain equilibrium. Secondly, based on the results of the study on the surface chemical properties of lecithin suspension, the aqueous phase reaction system of soybean lecithin catalyzed by enzymatic synthesis of glycerophosphate choline was constructed. The experimental results show that the initial substrate concentration is 20.0, the reaction temperature is 55 鈩，

本文編號：1567407