Characterization of oxysterols by electrospray ionization tandem mass spectrometry after one-step derivatization with dimethylglycine
Characterization of oxysterols by electrospray ionization tandem mass spectrometry after one-step derivatization with dimethylglycine
复制标题
DOI：
10.1002/rcm.2820
复制
发表时间：
2007-01-01
影响因子：
2
通讯作者：
Han, Xianlin
中科院分区：
文献类型：
--
作者：
Jiang, Xuntian;Ory, Daniel S.;Han, Xianlin
我们报道了一种新的方法，在1-乙基-3-（3-二甲氨基丙基）碳二亚胺和4-（N，N-二甲氨基）吡啶的存在下，用N，N-二甲基甘氨酸（DMG）衍生氧化甾醇的伯、仲和叔羟基，得到它们相应的单或二-DMG酯。研究了八种氧固醇，包括7-氧代胆固醇、5 α，6 α-和5 β，6 β-环氧胆固醇，以及7 α-、7 β-、24（S）-、25-和27-羟基胆固醇。这些单或双质子化衍生物的电喷雾电离串联质谱表征证明了每个氧甾醇衍生物的信息碎片模式的存在。提出并讨论了这些独特的碎片模式的生产潜在的解离途径。总的来说，这些信息丰富且独特的片段化模式允许快速和直接区分7 α-、7 β-、24（S）-、25-和27-羟基胆固醇异构体以及5 α，6 α-和5 β，6 β-环氧胆固醇异构体的身份，从而潜在地提供了与色谱分析相结合定量分析生物样品中氧固醇的基础。分居版权所有（c）2006约翰威利父子有限公司。
We report a novel approach to derivatize the primary, secondary, and tertiary hydroxy group(s) of oxysterols with N,N-dimethylglycine (DMG) in the presence of both 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and 4-(N,N-dimethylamino)pyridine to yield their corresponding mono- or di-DMG esters. Eight oxysterols including 7-oxocholesterol, 5 alpha,6 alpha- and 5 beta,6 beta-epoxycholesterols, as well as 7 alpha-, 7 beta-, 24(S)-, 25-, and 27-hydroxycholesterols, were studied. Electrospray ionization tandem mass spectrometric characterization of these singly or doubly protonated derivatives demonstrates the presence of an informative fragmentation pattern for each oxysterol derivative. Potential dissociation pathways for the production of these unique fragmentation patterns are proposed and discussed. Collectively, these informative and unique fragmentation patterns allow rapid and direct discrimination of the identities of 7 alpha-, 7 beta-, 24(S)-, 25-, and 27-hydroxycholesterol isomers, as well as 5 alpha,6 alpha- and 5 beta,6 beta-epoxycholesterol isomers, thereby potentially providing a foundation for quantitative analysis of oxysterols in biological samples in combination with a chromatographic separation. Copyright (c) 2006 John Wiley & Sons, Ltd.