With the recent ability to use combined liquid chromatography/electrospray tandem mass spectrometry to analyze for several eicosanoids in biological samples in a single and rapid experiment, heavy isotope-labeled eicosanoids are needed as internal standards in order to quantify eicosanoid analytes. The present study describes a practical preparation of cysteinyl leukotrienes (leukotriene C4, D4 and E4) with three 13C atoms and one 15N atom in the cysteinyl residue. The method involves solid-phase peptide synthesis to make glutathione with heavy isotopes in the cysteinyl residue and reaction of this tripeptide with commercially available leukotriene A4 methyl ester to give labeled leukotriene C4 methyl ester, which is hydrolyzed to labeled leukotriene C4. Labeled leukotriene E4 is prepared in the same way with the use of labeled cysteine. Labeled leukotriene D4 is prepared by treatment of labeled leukotriene C4 with commercially available γ-glutamyl transpeptidase. Copyright © 2007 John Wiley & Sons, Ltd.
近年来,利用
液相色谱/电喷雾串联质谱联用技术可以在一次实验中快速分析
生物样本中的多种类二十
烷烃,因此需要用重同位素标记的类二十
烷烃作为内标物,以便对类二十
烷烃分析物进行定量分析。本研究介绍了一种在半胱
氨酰残基中含有三个 13C 原子和一个 15N 原子的半胱
氨酰
白三烯(
白三烯 C4、
D4 和 E4)的实用制备方法。该方法包括固相肽合成,以制造半胱
氨酰残基中含有重同位素的
谷胱甘肽,并将该三肽与市售的
白三烯 A4 甲酯反应,得到标记的
白三烯 C4 甲酯,再将其
水解为标记的
白三烯 C4。标记
白三烯 E4 的制备方法与使用标记半胱
氨酸的方法相同。标记的
白三烯 D4 是用市售的γ-谷
氨酰转肽酶处理标记的
白三烯 C4 制备的。Copyright © 2007 John Wiley & Sons, Ltd. All Rights Reserved.