Quantitation of choline and its metabolites in tissues and foods by liquid chromatography/electrospray ionization-isotope dilution mass spectrometry
Quantitation of choline and its metabolites in tissues and foods by liquid chromatography/electrospray ionization-isotope dilution mass spectrometry
复制标题
DOI：
10.1021/ac025624x
复制
发表时间：
2002-09-15
影响因子：
7.4
通讯作者：
Zeisel, SH
中科院分区：
文献类型：
--
作者：
Koc, H;Mar, MH;Zeisel, SH
胆碱对于正常的膜功能、乙酰胆碱合成、脂质转运和甲基代谢很重要。美国国家科学院最近制定了人类饮食中胆碱的要求。在组织和食物中，有多种胆碱化合物有助于胆碱含量。甜菜碱，一种胆碱的衍生物，也很重要，因为它在将甲基捐赠给同型半胱氨酸以形成甲硫氨酸中的作用。放射性同位素、高压液相色谱和气相色谱/同位素稀释质谱（GC/IDMS）方法可用于测量胆碱。然而，这些现有的方法是繁琐和耗时的，并且没有测量所有感兴趣的化合物。在这项研究中，我们描述了一种新的方法定量胆碱，甜菜碱，乙酰胆碱，甘油磷酸胆碱，胞苷二磷酸胆碱，磷酸胆碱，磷脂酰胆碱，鞘磷脂在肝脏，血浆，各种食物，和大脑使用液相色谱/电喷雾电离-同位素稀释质谱（LC/ESI-IDMS）。胆碱化合物通过甲醇和氯仿萃取并分配到有机相和水相，并直接通过LC/ESI-IDMS分析，而不需要如GC/IDMS方法所要求的那样单独分离和衍生化每种化合物。使用现有已发表的GC/IDMS方法对新的LC/ESI/IDMS方法进行了验证。
Choline is important for normal membrane function, acetylcholine synthesis, lipid transport, and methyl metabolism. The U.S. National Academy of Sciences recently set requirements for choline in the human diet. In tissues and foods, there are multiple choline compounds that contribute to choline content. Betaine, a derivative of choline, is also important because of its role in donation of methyl groups to homocysteine to form methionine. Radioisotopic, high-pressure liquid chromatography, and gas chromatography/isotope dilution mass spectrometry (GC/IDMS) methods are available for measurement of choline. However, these existing methods are cumbersome and time-consuming, and none measures all of the compounds of interest. In this study, we describe a new method for quantitation of choline, betaine, acetylcholine, glycerophosphocholine, cytidine diphosphocholine, phosphocholine, phosphatidylcholine, and sphingomyelin in liver, plasma, various foods, and brain using liquid chromatography/electrospray ionization-isotope dilution mass spectrometry (LC/ESI-IDMS). Choline compounds were extracted by and partitioned into organic and aqueous phases using methanol and chloroform and analyzed directly by LC/ESI-IDMS without the need for isolation and derivatization of each compound separately as was required by the GC/IDMS method. The new LC/ESI/IDMS method was validated using the existing published GC/IDMS method.