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(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：磷脂酰膽堿(PC)及其水解產(chǎn)物L(fēng)-α-甘油磷酸膽堿(GPC)廣泛應(yīng)用于醫(yī)藥和保健品領(lǐng)域。以磷脂酰膽堿為基礎(chǔ)的生物轉(zhuǎn)化產(chǎn)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(xué)性質(zhì)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(zhuǎn)化提供了新的催化體系。論文首先將大豆卵磷脂高速均質(zhì)為水相的卵磷脂懸浮液,對卵磷脂在水相中的表面化學(xué)性質(zhì)進行了研究。結(jié)果表明:當(dāng)緩沖液pH增加時,顆粒粒徑變大,體系的電導(dǎo)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(xiàn)波動,pH出現(xiàn)略微下降后最終保持在4.70左右,電導(dǎo)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(xué)性質(zhì)研究結(jié)果為基礎(chǔ),構(gòu)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(yīng)體系,并對其催化條件進行了研究。實驗結(jié)果得到:初始底物濃度為20.0%,反應(yīng)溫度為55℃,初始pH為5.0,酶用量為87.03U/g,當(dāng)反應(yīng)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(yīng)6h,反應(yīng)的PC轉(zhuǎn)化率達(dá)到90%左右。補料調(diào)節(jié)底物濃度的方式有利于酶催化反應(yīng)的進行。論文最后研究了水相酶催化反應(yīng)后的產(chǎn)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(zhì),萃取時二氯甲烷用量為反應(yīng)液體積的0.4倍,甲醇的用量為0.5倍。產(chǎn)物經(jīng)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(chǎn)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(guān)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(shù),并在此體系中制備得到了 GPC產(chǎn)品,研究結(jié)果為綠色環(huán)保的磷脂酰膽堿生物轉(zhuǎn)化技術(shù)提供理論依據(jù)。
[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