ELECTROSPRAY COLLISION-INDUCED DISSOCIATION MASS-SPECTROMETRY OF MONO-HYDROXYLATED, DI-HYDROXYLATED AND TRI-HYDROXYLATED LIPOXYGENASE PRODUCTS, INCLUDING LEUKOTRIENES OF THE B-SERIES AND LIPOXINS

Collision-induced dissociation (CID) mass spectra were recorded on und erivatized, hydroxylated lipoxygenase products, including 5(S)-, 12(S) - and 15(S)-hydroxyeicosatetraenoic acids (HETE), leukotriene (LT) B-4 , LTB(5), the LTB(4) metabolites 20-OH-LTB(4), 20-COOH-LTB(4) and 10,1 1-dihydro-LTB(4), the LTB(4) isomers 6-trans-LTB(4), 6-trans,12-epi-LT B(4) and 5(S),12(S)-dihydroxyeicosatetraenoic acid (diHETE) as well as 5(S),6(R)-diHETE, 14(S), 15(R)-diHETE and lipoxin (LX) A, and B,. Pse udomolecular [M-H](-) parent ions were generated by electrospray ioniz ation. The ions were accelerated to 4 keV, selected by the double focu sing sectors of a hybrid tandem mass spectrometer, decelerated to 400 eV and focused into a collision cell containing xenon. The resulting f ragment ions were mass analysed by an orthogonal time-of-flight analys er. The CID spectra obtained were structurally informative allowing is omer differentiation.