Lipids

, Volume 33, Issue 9, pp 843–852

Analysis of novel hydroperoxides and other metabolites of oleic, linoleic, and linolenic acids by liquid chromatography-mass spectrometry with ion trap MSn

  • Ernst H. Oliw
  • Chao Su
  • Torun Skogström
  • Günther Benthin
Article

DOI: 10.1007/s11745-998-0280-0

Cite this article as:
Oliw, E.H., Su, C., Skogström, T. et al. Lipids (1998) 33: 843. doi:10.1007/s11745-998-0280-0

Abstract

Linoleate is oxygenated by manganese-lipoxygenase (Mn-LO) to 11S-hydroperoxylinoleic acid and 13R-hydroperoxyoctadeca-9Z,11E-dienoic acid, whereas linoleate diol synthase (LDS) converts linoleate sequentially to 8R-hydroperoxylinoleate, through an 8-dioxygenase by insertion of molecular oxygen, and to 7S,8S-dihydroxylinoleate, through a hydroperoxide isomerase by intramolecular oxygen transfer. We have used liquid chromatography-mass spectrometry (LC-MS) with an ion trap mass spectrometer to study the MSn mass spectra of the main metabolites of oleic, linoleic, α-linolenic and γ-linolenic acids, which are formed by Mn-LO and by LDS. The enzymes were purified from the culture broth (Mn-LO) and mycelium (LDS) of the fungus Gaeumannomyces graminis. MS3 analysis of hydroperoxides and MS2 analysis of dihydroxy- and monohydroxy metabolites yielded many fragments with information on the position of oxygenated carbons. Mn-LO oxygenated C-11 and C-13 of 18∶2n−6, 18∶3n−3, and 18∶3n−6 in a ratio of ∼1∶1–3 at high substrate concentrations. 8-Hydroxy-9(10)expoxystearate was identified as a novel metabolite of LDS and oleic acid by LC-MS and by gas chromatography-MS. We conclude that LC-MS with MSn is a convenient tool for detection and identification of hydroperoxy fatty acids and other metabolites of these enzymes.

Abbreviations

APCI

atmospheric pressure chemical ionization

7,8-DiHODE

7S,8S-dihydroxy-9Z,12Z-octadecadienoic acid

7,8-DiHOME

7S,8S-dihydroxy-9Z-octadecenoic acid

7,8-DiHOTrE

7S,8S-dihydroxy-9Z,12Z,15Z-octadecatrienoic acid

ESI

electrospray ionization

GC-MS

gas chromatography-mass spectrometry

HETE

hydroxyeicosatetraenoic acid

HPLC

high-performance liquid chromatography

8-H(P)ODE

8R-hydro(pero)xy-9Z,12Z-octadecadienoic acid

11-H(P)ODE

11S-hydro(pero)-xy-9Z,12Z-octadecadienoic acid

13-H(P)ODE

13-hydro(pero)xy-9Z,11E-octadecadienoic acid

8-H(P)OME

8R-hydro(pero)xy-9Z-octadecenoic acid

8-HPOTrE

8R-hydroperoxy-9Z,12Z,15Z-octadecatrienoic acid

11-H(P)OTrE(n-6)

11S-hydro(pero)xy-6Z,9Z,12Z-octadecatrienoic acid

11-H(P)OTrE

11S-hydro(pero)xy-9Z,12Z,15Z-octadecatrienoic acid

13-H(P)OTrE

13-hydro(pero)xy-9Z,11E,15Z-octadecatrienoic acid

13-H(P)OTrE(n-6)

13-hydro(pero)xy-6Z,9Z,11E-octadecatrienoic acid

LC-MS

liquid chromatography-mass spectrometry

LDS

linoleate diol synthase

Mn-LO

manganese lipoxygenase

PGH

prostaglandin H

RP-HPLC

reversed phase-HPLC

Copyright information

© AOCS Press 1998

Authors and Affiliations

  • Ernst H. Oliw
    • 1
  • Chao Su
    • 1
  • Torun Skogström
    • 1
  • Günther Benthin
    • 1
  1. 1.Division of Biochemical Pharmacology, Department of Pharmaceutical Biosciences, Uppsala Biomedical CenterUppsala UniversityUppsalaSweden

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