Synthesis of DHA/EPA-rich phosphatidylcholine by immobilized phospholipase A1: effect of water addition and vacuum condition
Synthesis of DHA/EPA-rich phosphatidylcholine by immobilized phospholipase A1: effect of water addition and vacuum condition
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DOI：
10.1007/s00449-016-1609-6
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发表时间：
2016-04
影响因子：
3.8
通讯作者：
Daoming Li;Xiaoli Qin;Weifei Wang;Zhigang Li;Bo Yang;Yonghua Wang
中科院分区：
文献类型：
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作者：
Daoming Li;Xiaoli Qin;Weifei Wang;Zhigang Li;Bo Yang;Yonghua Wang
通过固定化磷脂酶 A1(PLA1) 催化 PC 和富含 DHA/EPA 的乙酯在无溶剂体系中的酯交换反应，成功合成了富含 DHA/EPA 的磷脂酰胆碱 (PC)。使用响应面法（RSM）评估反应温度、加水量和底物质量比对DHA/EPA掺入的影响。加水对掺入的影响最为显着。然而，反应温度和底物质量比对掺入没有显着影响。在以下条件下，最大掺入率为 19.09%（24 小时）：温度 55.7 °C，加水量 1.1 wt%，底物质量比（乙酯/PC）6.8:1。此外，还进一步研究了水添加（0 至 1.25 wt%）对 DHA/EPA 掺入和产品组成的影响。当水添加量高于 0.5 wt% 时，固定化的 PLA1 活性更高。通过监测不同加水量的反应过程，提出了 PC 与富含 DHA/EPA 的乙酯进行酯交换反应的可能反应方案。总之，在反应早期阶段，混合物中以 PC 和 sn2-溶血磷脂酰胆碱 (LPC) 为主，而在反应后期，混合物中以 sn1-LPC 和甘油磷酸胆碱 (GPC) 为主。 24 h后采用真空显着增加了DHA/EPA的掺入量和PC的组成，并且在72 h时获得了最高的DHA/EPA掺入量（30.31%），PC的产率为47.2%。
DHA/EPA-rich phosphatidylcholine (PC) was successfully synthesized by immobilized phospholipase A1(PLA1)-catalyzed transesterification of PC and DHA/EPA-rich ethyl esters in a solvent-free system. Effects of reaction temperature, water addition and substrate mass ratio on the incorporation of DHA/EPA were evaluated using response surface methods (RSM). Water addition had most significant effect on the incorporation. Reaction temperature and substrate mass ratio, however, had no significant effect on the incorporation. The maximal incorporation was 19.09 % (24 h) under the following conditions: temperature 55.7 °C, water addition 1.1 wt % and substrate mass ratio (ethyl esters/PC) 6.8:1. Furthermore, effects of water addition (from 0 to 1.25 wt %) on DHA/EPA incorporation and the composition of products were further investigated. The immobilized PLA1was more active when water addition was above 0.5 wt %. By monitoring the reaction processes with different water addition, a possible reaction scheme was proposed for transesterification of PC with DHA/EPA-rich ethyl esters. In summary, PC and sn2-lysophosphatidylocholine (LPC) were predominant in the mixtures at early stages of reaction, whereas sn1-LPC and glycerophosphocholine (GPC) predominant at later stages. The vacuum employed after 24 h significantly increased the incorporation of DHA/EPA and the composition of PC, and the highest incorporation (30.31 %) of DHA/EPA was obtained at 72 h and the yield of PC was 47.2 %.