Facile preparation of leukotrienes C4, D4 and E4 containing carbon-13 and nitrogen-15 for quantification of cysteinyl leukotrienes by mass spectrometry
✍ Scribed by Farideh Ghomashchi; James G. Bollinger; Michael H. Gelb
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- French
- Weight
- 106 KB
- Volume
- 50
- Category
- Article
- ISSN
- 0022-2135
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✦ Synopsis
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 C 4 , D 4 and E 4 ) with three 13 C atoms and one 15 N 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 A 4 methyl ester to give labeled leukotriene C 4 methyl ester, which is hydrolyzed to labeled leukotriene C 4 . Labeled leukotriene E 4 is prepared in the same way with the use of labeled cysteine. Labeled leukotriene D 4 is prepared by treatment of labeled leukotriene C 4 with commercially available g-glutamyl transpeptidase.