Synthesis of Structured Phospholipids Containing Polyunsaturated Fatty Acid and Their Functional Evaluation

最近有报道称，磷脂酰丝氨酸（一种天然磷脂）和二十二碳六烯酸（一种多不饱和脂肪酸）对人脑神经系统都有积极作用。正因为如此，它们作为有助于大脑健康的功能性食品或医用材料而备受人们的关注。本文的目的是合成一种脂肪酸残基为DHA的结构磷脂酰丝氨酸，并评价其在培养神经细胞中的功能。1)从自然界中含量最丰富的磷脂——磷脂酰胆碱出发，通过酶（磷脂酶A_2和D）结合化学去酰化和酰化（酯化）合成了三种结构磷脂。它们是1,2-二二十二碳六烯酰基磷脂酰胆碱（DDC）、1,2-二二十二碳六烯酰基磷脂酰丝氨酸（DBS）和1-油基-2-二十二碳六烯酰基磷脂酰丝氨酸（ODS）。2)首先从大鼠胎脑中制备脑神经细胞，在DMEM/F-12混合培养基中培养。通过测定细胞凋亡释放的乳糖脱氢酶活性，评价在培养过程中加入合成磷脂等各种化合物对细胞死亡的保护或恶化作用。并对β淀粉样蛋白诱导神经元损伤的保护作用进行了评价。3) DDC、DDS和ODS对培养条件下细胞自然死亡无抑制作用。然而，我们观察到DDC、DDS和ODS对添加淀粉样蛋白β1-42诱导的神经元损伤具有保护作用。

It has been recently reported that both phosphatidylserine (a kind of natural phospholipids) and docosahexaenoic acid (DHA, a kind of polyunsaturared fatty acids) have positive effects on human brain neural system. Because of them, they have attracted much the attention of people as functional foods or medical materials that contribute to brain health. The objective of this work is to synthesize a structured phosphatidylserine whose fatty acid residue is DHA, and to evaluate its function in cultured neural cells.1)Starting from phosphatidylcholine which is the most abundant phspholipid in nature, three kinds of structured phospholipids have been synthesized chomo-enzymatically : i.e., by using enzymes (phospholipases A_2 and D) combined with chemical deacylation and acylation (esterification). They are 1,2-didocosahexaenoyl-phosphatidylcholine(DDC), 1,2-didocosahexaenoyl-phsphatidylserine (DBS), and 1-oleoyl-2-docosahexaenoyl-phosphatidylserine(ODS).2)Brain neural cells were first prepared from rat fetal brain and cultured in DMEM/F-12 mixed medium. Adding various compounds including the synthesized phospholipids, protective or deteriorating effect on the cell death in the culture was evaluated by determining activity of lactose dehydrogenase released from apoptosis of the cells. Also, their protecting effect was evaluated from neuron damage induced by amyloid β protein in the culture.3)Depressive effects of DDC,DDS and ODS were not observed on natural cell death caused in the culture condition. However, it was observed that DDC,DDS and ODS protected from the neuron damage induced by added amyloid β1-42 protein.