Separation of Cis-Trans Phospholipid Isomers Using Reversed Phase LC with High Resolution MS Detection
Separation of Cis-Trans Phospholipid Isomers Using Reversed Phase LC with High Resolution MS Detection
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DOI：
10.1021/ac300953j
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发表时间：
2012-07-03
影响因子：
7.4
通讯作者：
Kristal, Bruce S.
中科院分区：
文献类型：
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作者：
Bird, Susan S.;Marur, Vasant R.;Kristal, Bruce S.
西方饮食中合成反式脂肪酸的增加已被证明对生理有有害影响，并增加了个人患代谢性疾病、心血管疾病和中风的风险。这些脂肪酸对健康的重要性及其(病理)生理作用的多样性表明，不仅应该研究游离反式脂肪酸，而且监测这些脂肪是否存在于甘油磷脂等生物脂的侧链中也是至关重要的。我们开发了一种高分辨率的LC-MS方法，以高效、灵敏和稳健的方式定量监测生物样品中发现的主要脂类，同时还通过使用高能碰撞解离(HCD)碎裂和层析比对来表征单个脂类侧链。我们在这里展示了这种前面描述的反相法如何在正负两种模式下通过两条18：1的侧链基线分离磷脂酰甘油和磷脂酰胆碱(PC)的顺反异构体，作为整齐的溶液并添加到生物基质中。在线粒体和血清图谱研究中，内源性PC(18：1/18：1)-顺式和PC(18：1/18：1)-反式异构体被检测，其中大鼠饲喂富含反式18：1脂肪酸或顺式18：1脂肪酸的饲料。在这项研究中，我们测定了PC的顺反异构体比例(18：1/18：1)，并将这一比例与饲料组成相关联。这种通用的LC-MS方法能够在非靶向方法的背景下监测生物脂质中的反式脂肪，从而允许相对定量和增强对复杂基质中未知脂质的识别。
The increased presence of synthetic trans fatty acids into western diets has been shown to have deleterious effects on physiology and raising an individual's risk of developing metabolic disease, cardiovascular disease, and stroke. The importance of these fatty acids for health and the diversity of their (patho) physiological effects suggest that not only should the free trans fatty acids be studied but also monitoring the presence of these fats into the side chains of biological lipids, such as glycerophospholipids, is also essential. We developed a high resolution LC-MS method that quantitatively monitors the major lipid classes found in biospecimens in an efficient, sensitive, and robust manner while also characterizing individual lipid side chains through the use of high energy collisional dissociation (HCD) fragmentation and chromatographic alignment. We herein show how this previously described reversed phase method can baseline separate the cis-trans isomers of phosphatidylglycerol and phosphatidylcholine (PC) with two 18:1 side chains, in both positive and negative mode, as neat solutions and when spiked into a biological matrix. Endogenous PC (18:1/18:1)-cis and PC (18:1/18:1)-trans isomers were examined in mitochondrial and serum profiling studies, where rats were fed diets enriched in either trans 18:1 fatty acids or cis 18:1 fatty acids. In this study, we determined the cis:trans isomer ratios of PC (18:1/18:1) and related this ratio to dietary composition. This generalized LC-MS method enables the monitoring of trans fats in biological lipids in the context of a nontargeted method, allowing for relative quantitation and enhanced identification of unknown lipids in complex matrixes.