Abstract:

Homologues separation is a key process in the production of high-purity drugs and chemicals. High-purity phosphatidylserine (PS) is widely used as drugs and functional additives; however PS often appears in a mixture with structurally similar homologues and the selective separation of phospholipid homologues remains challenging. Here, a novel extraction method was developed to separate PS and phosphatidylcholine (PC) with ionic liquids (ILs) as extractants. The effects of structure and concentration of ILs and temperature on extraction performance were investigated. The results showed that the structure of the IL's anion had a significant impact on the separation selectivity, and an obvious synergistic extraction effect between IL and polar diluent was observed. In 1-ethyl-3-methylimidazolium bromide([EMIm]Br)-methanol-hexane biphasic systems, the selectivity of PC to PS (S_PC/PS) reached up to 29.48, when the mole fraction of IL was only 5%. Additionally, ab initio calculations were used to explore the extraction mechanism, and the results indicated that the multiple hydrogen-bonding and electrostatic interactions were formed between phospholipids and ILs, which is probably beneficial for the selective separation of phospholipid homologues.

Key words: ionic liquids, separation, extraction, phosphatidylserine, phosphatidylcholine

摘要：

同系物分离是高纯度药物单体和化学品制备中的重要环节，磷脂酰丝氨酸是一类重要的药物和功能添加剂，其制备过程中的关键技术是磷脂酰丝氨酸与其他磷脂同系物的分离，但同系物之间结构相似、分离难度大。报道了以离子液体为介质选择性萃取分离磷脂酰丝氨酸和磷脂酰胆碱的方法，系统研究了离子液体结构和浓度、萃取温度对分离性能的影响。研究表明，离子液体的阴离子结构显著影响同系物的分离选择性，且离子液体与极性稀释剂之间存在协同萃取效应，离子液体的摩尔浓度仅为5%时，1-乙基-3-甲基咪唑溴/甲醇-正己烷两相体系中的磷脂酰丝氨酸和磷脂酰胆碱的选择性高达29.48。采用量子化计算初步研究了萃取机理，结果表明离子液体与磷脂之间形成了多重氢键和静电相互作用，从而促进了磷脂同系物之间的选择性分离。

关键词: 离子液体, 分离, 萃取, 磷脂酰丝氨酸, 磷脂酰胆碱