Molecular species composition of rat liver phospholipids by ESI-MS/MS: the effect of chromatography.
Molecular species composition of rat liver phospholipids by ESI-MS/MS: the effect of chromatography.
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发表时间：
2001-12
影响因子：
6.5
通讯作者：
Cynthia J. DeLong;Paul R. S. Baker;M. Samuel;Zheng Cui;Michael J. Thomas
中科院分区：
文献类型：
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作者：
Cynthia J. DeLong;Paul R. S. Baker;M. Samuel;Zheng Cui;Michael J. Thomas
使用电喷雾离子化串联质谱（ESI-MS/MS），这项研究表明，损失的甘油磷脂（GPL）色谱后的GPL分子种类分布不均。TLC和HPLC均导致具有0至3个双键的GPL优先损失：胆碱甘油磷酸（PC）分别为20%和7.2%，乙醇胺甘油磷酸（PE）分别为19.7%和7.5%。这些损失的结果是，含有四个或更多双键的脂肪酸的GPL对色谱后的总量有更大的贡献。ESI-MS/MS分析还表明，具有四个或更多双键的PC分子物种迁移到PC的TLC带的前端。从TLC板中提取的GPL偶尔含有比原始提取物中更小的PC。这些低分子量的PC很容易被还原成醇，并与2，4-二硝基苯肼形成衍生物，这表明醛是由不饱和脂肪酸氧化产生的。通过ESI-MS/MS直接分析脂质提取物，无需进行初步色谱分离，即可准确分析脂质混合物中的GPL分子种类。然而，在相对低浓度的GPL下，电喷雾射流中磷脂的电离最大化。对于PC和PE，在1-2 nmol/ml左右的浓度下，磷脂质量和离子强度之间存在线性响应。总离子强度随浓度高于1-2 nmol/ml继续增加，但响应是非线性的。
Using electrospray ionization tandem mass spectrometry (ESI-MS/MS) this study shows that the loss of glycerophospholipid (GPL) after chromatography was unevenly distributed across the GPL molecular species. Both TLC and HPLC caused a preferential loss of GPL with 0 to 3 double bonds: 20% and 7.2% for choline glycerophosphates (PC) and 19.7% and 7.5% for ethanolamine glycerophosphates (PE), respectively. A consequence of these losses was that GPLs containing fatty acids with four or more double bonds had a greater contribution to the total after chromatography. ESI-MS/MS analysis also showed that PC molecular species with four or more double bonds migrated at the front of the TLC band of PCs. GPLs extracted from TLC plates occasionally contained PCs that were smaller than those in the original extract. These low molecular mass PCs were easily reduced to alcohols and formed derivatives with 2,4-dinitrophenylhydrazine, suggesting that aldehydes were generated by the oxidation of unsaturated fatty acids. Directly analyzing lipid extracts by ESI-MS/MS without preliminary chromatographic separation gives an accurate distribution of GPL molecular species in lipid mixtures. However, the ionization of the phospholipids in the electrospray jet maximized at relatively low concentrations of GPL. There was a linear response between phospholipid mass and ion intensity for concentrations around 1-2 nmol/ml for both PC and PE. The total ion intensity continued to increase with concentrations above 1-2 nmol/ml, but the response was non-linear.