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The AAPS Journal

, Volume 8, Issue 4, pp E655–E660 | Cite as

Endocannabinoid metabolomics: A novel liquid chromatography-mass spectrometry reagent for fatty acid analysis

  • John Williams
  • Lakshmipathi Pandarinathan
  • Jodi Anne Wood
  • Paul Vouros
  • Alexandros Makriyannis
Article

Abstract

We have synthesized 4,4-dimethoxyoxazoline derivatives of several fatty acids associated with the endocannabinoid metabolome using tris(hydroxymethyl)aminomethane in a 1-step reaction by microwave irradiation. The derivatization incorporates a nitrogen into the final product, which allows for improved detection by liquid chromatographymass spectrometry in positive atmospheric pressure chemical ionization (APCI) mode. Palmitic and oleic acid derivatives show a 200-fold increase in sensitivity compared with the free acids when analyzed in negative-mode APCI. In addition to improving sensitivity, the oxazoline derivatization creates a similar ionization response for the fatty acids tested, which simplifies their quantitation. Fatty acid oxazoline derivatives can be detected using the same conditions optimized for the endocannabinoids, which allows for a simultaneous quantitation of the entire endocannabinoid metabolome.

Keywords

fatty acids LC-MS metabolome oxazoline derivatives microwave synthesis 

References

  1. 1.
    Bazinet R, Lee H, Felder C, Porter A, Rappaport S, Rosenberger T. Rapid high energy microwave fixation is required to determine the anandamide (N-arachidonoylethanolamine) concentration of rat brain. Neurochem Res. 2005;30:597–601.PubMedCrossRefGoogle Scholar
  2. 2.
    Di Marzo V, Breivogel C, Tao Q, et al. Levels, metabolism, and pharmacological activity of anandamide in CB1 cannabinoid receptor knockout mice. J Neurochem. 2000;75:2434–2443.PubMedCrossRefGoogle Scholar
  3. 3.
    Byrdwell W. Atmospheric pressure chemical ionization mass spectrometry for analysis of lipids. Lipids. 2001;36:327–346.PubMedCrossRefGoogle Scholar
  4. 4.
    Spitzer V Structure analysis of fatty acids by gas chromatography—low resolution electron impact mass spectrometry of their 4,4-dimethyloxazoline derivatives—a review. Prog Lipid Res. 1996;35:387–408.PubMedCrossRefGoogle Scholar
  5. 5.
    Ryhage R, Stenhagen E. Mass spectrometry in lipid research. J Lipid Res. 1960;1:361–390.PubMedGoogle Scholar
  6. 6.
    Sharkey A, Shultz JL, Friedel RA. Mass spectra of esters. Formation of rearrangement ions. Anal Chem. 1959;31:87–94.CrossRefGoogle Scholar
  7. 7.
    Zhang JY, Yu QT, Liu BN, Huang ZH. Chemical modifications in mass spectrometry, IV: 2-alkenyl-4,4-dimethyloxazolines as derivatives for the double bond location of long-chain olefinic acids. Biomed Environ Mass Spectrom. 1988;15:33–44.CrossRefGoogle Scholar
  8. 8.
    Fay L, Richli U. Location of double bonds in polyunsaturated fatty acids by gas chromatography-mass spectrometry after 4,4 dimethyloxazoline derivatization. J Chromatogr. 1991;541:89–98.CrossRefGoogle Scholar
  9. 9.
    Kuklev DV, Smith WL. A procedure for preparing oxazolines of highly unsaturated fatty acids to determine double bond positions by mass spectrometry. J Lipid Res. 2003;44:1060–1066.PubMedCrossRefGoogle Scholar
  10. 10.
    Garrido JL, Medina I. One step conversion of fatty acids into their 2-alkenyl-4,4-dimethyloxazoline derivatives directly from total lipids. J Chromatogr A. 1994;673:101–105.CrossRefGoogle Scholar
  11. 11.
    Crosignani S, Young AC, Linclau B. Synthesis of 2-oxazolines mediated by N,N′-diisopropylcarbodiimide. Tetrahedron Lett. 2004;45:9611–9615.CrossRefGoogle Scholar
  12. 12.
    Garcia-Tellado F, Loupy A, Petti A, Marrero-Terrero AL. Solventfree microwave-assisted efficient synthesis of 4,4-disubstituted-2-oxazolines. Eur J Org Chem. 2003;22:4387–4391.CrossRefGoogle Scholar

Copyright information

© American Association of Pharmaceutical Scientists 2006

Authors and Affiliations

  • John Williams
    • 1
    • 2
  • Lakshmipathi Pandarinathan
    • 1
  • Jodi Anne Wood
    • 1
  • Paul Vouros
    • 2
  • Alexandros Makriyannis
    • 1
  1. 1.Center for Drug DiscoveryNortheastern UniversityBoston
  2. 2.Barnett Institute and Department of ChemistryNortheastern UniversityBoston

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