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Characterization of hydroxyeicosatetraenoic acids and hydroxyeicosatetraenoic acid phosphatidylcholines by liquid secondary ion tandem mass spectrometry
Author(s) -
Zhang Ji Y.,
Nobes Brian J.,
Wang Jiemin,
Blair Ian A.
Publication year - 1994
Publication title -
biological mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1052-9306
DOI - 10.1002/bms.1200230704
Subject(s) - hydroxyeicosatetraenoic acid , chemistry , tandem mass spectrometry , phosphatidylcholine , mass spectrometry , structural isomer , ion , analytical chemistry (journal) , arachidonic acid , chromatography , stereochemistry , organic chemistry , phospholipid , biochemistry , membrane , enzyme
Arachidonic acid is oxidized to regioisomeric 5( S )‐, 12( S )‐ and 15( S )‐hydroxyeicosatetraenoic acids by the corresponding 5‐, 12‐ and 15‐lipoxygenases. These hydroxylated fatty acids can then be incorporated into cellular phos‐pholipids. Negative liquid secondary ion tandem mass spectrometry using a high‐energy collision regime in a tandem four‐sector mass spectrometer was used to characterize regioisomeric hydroxyeicosatetraenoic acids and the corresponding hydroxyeicosatetraenoic phosphatidylcholine species. Collision‐induced dissociation (CID) of the [M − H] − negative ion at m/z 319 from the hydroxyeicosatetraenoic acids regioisomers produced some similar product ions, such as m/z 301 [M − H − H 2 O] − and m/z 257 [M − H − (H 2 O + CO 2 )]‐. In addition, product ions characteristic of the particular hydroxyeicosatetraenoic acid were formed from α cleavages adjacent to the hydroxyl moieties. Negative liquid secondary ion mass spectrometry of purified hydroxyeicosatetraenoate phosphatidylcholine species gave an ion at m/z 810 [M − CH 3 ] ‐. CID of the m/z 810 ion gave product ions at m/z 283 and m/z 319, corresponding to stearate at the sn‐1 position and hydroxyeicosatetraenoate at the sn‐2 position, respectively. From CID of the negative ion at m/z 319 and examination of the product ion spectra, the hydroxyeicosatetraenoate regioisomer present in the phosphatidylcholine could be identified.