Analysis of Epoxyeicosatrienoic and Monohydroxyeicosatetraenoic Acids Esterified to Phospholipids in Human Red Blood Cells by Electrospray Tandem Mass Spectrometry

A liquid chromatography/mass spectrometric method for simultaneous analysis of arachidonic acid and its endogenous eicosanoid metabolites prostaglandins, dihydroxyeicosatrienoic acids, hydroxyeicosatetraenoic acids, and epoxyeicosatrienoic acids in rat brain tissue

“…Although a few LC/MS or LC/MS/MS (either with chromatographic separation or flow injection analysis) methods have been used for identification and quantification of either single eicosanoid [29], or various PGs [30], or PGs together with HETEs [31][32][33][34][35][36], or various DiHETrEs [37], or HETEs together with EETs [38,39] or HETEs, EETs, together with DiHETrEs [40] in various biological matrices in a single analysis, we could not identify a published mass spectrometric-based method for the simultaneous identification and quantification of PGs, DiHETrEs, HETEs, EETs, and parent compound AA in biological matrices, including brain tissue. In addition, the method validation data were not available in most of these methods.…”

Structural characterization of monohydroxyeicosatetraenoic acids and dihydroxy- and trihydroxyeicosatrienoic acids by ESI-FTICR

“…The characteristic product ions of 15-HETE were m/z 219, 175, and 113 and were similar to previous studies [33,39]. The m/z 219 was the product ion formed by the identical mechanism as previously described for the m/z 179 of 12-HETE [41].…”

“…In the SORI-CID spectrum of [M Ϫ H] Ϫ for 11-HETE, the major characteristic product ions were m/z 167 and 149. The characteristic m/z 167 is similar to that reported fragmentation by triple quadrupole and ion trap mass spectrometers [33,39,41]. The MS/MS spectra for 11-HETE by a triple quadrupole mass spectrometer had the dominant ion of m/z 167 [33], while spectra from FTICR and ion trap [39] contained other characteristic ions.…”

“…Ϫ ion formed the highest abundant m/z 257, although these two ions were not detected in the previous studies [33,41] …”

“…Previous studies showed that HETEs and DHETs form characteristic fragments during MS 2 analysis by ion trap and triple quadrupole mass spectrometers [32][33][34][35][36][37][38][39][40]. The mechanisms for electrospray ionization and tandem mass spectrometry of various classes of eicosanoids have been elegantly reviewed [41].…”