, Volume 43, Issue 6, pp 533–548

The Identification of Mono-, Di-, Tri-, and Tetragalactosyl-diacylglycerols and their Natural Estolides in Oat Kernels

  • Robert A. Moreau
  • Douglas C. Doehlert
  • Ruth Welti
  • Giorgis Isaac
  • Mary Roth
  • Pamela Tamura
  • Alberto Nuñez
Original Article


Oat kernels were extracted with methanol, and glycolipid-enriched fractions were prepared using silica solid phase extraction. Using direct infusion electrospray ionization (ESI) tandem mass spectrometry (MS), high performance liquid chromatography (HPLC)-ESI-MS, and HPLC-atmospheric pressure chemical ionization (APCI)-MS, we confirmed previous reports that digalactosyldiacylglycerol (DGDG) was the most abundant glycolipid in oat kernels and confirmed a previous report of the presence of a DGDG mono-estolide in oat kernels. In the current study we also identified several additional natural galactolipid estolides: two new DGDG estolides (di- and tri-estolides), two trigalactosyldiacylglycerol (TriGDG) estolides (mono- and di-estolides), and one tetragalactosyldiacylglycerol (TetraGDG) estolide (mono-estolide). The levels of total galactolipid estolides in oat kernels were estimated to be about 29% of the total glycolipid fraction. To our knowledge, this report is the first evidence of natural di- and tri-estolides of polar lipids.


Oat kernels Estolides Digalactosyldiacylglycerol Trigalactosyldiacylglycerol Tetragalactosyldiacylglycerol Galactolipid Mass spectrometry 



Atmospheric pressure chemical ionization


Collision-induced dissociation








Electrospray ionization


Evaporative light scattering detector


Extracted ion chromatogram


High-performance liquid chromatography


Mass spectrometry




Neutral loss






Solid phase extraction


Tandem mass spectrometry




Total ion chromatogram






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Copyright information

© US Government 2008

Authors and Affiliations

  • Robert A. Moreau
    • 1
    • 4
  • Douglas C. Doehlert
    • 2
  • Ruth Welti
    • 3
  • Giorgis Isaac
    • 3
  • Mary Roth
    • 3
  • Pamela Tamura
    • 3
  • Alberto Nuñez
    • 1
  1. 1.US Department of AgricultureAgricultural Research Service, Eastern Regional Research CenterWyndmoorUSA
  2. 2.US Department of AgricultureAgricultural Research Service, Cereal Crops Research UnitFargoUSA
  3. 3.Kansas Lipidomics Research Center, Division of BiologyKansas State UniversityManhattanUSA
  4. 4.Crop Conversion Science and Engineering Research Unit, ERRC, ARS, USDAWyndmoorUSA

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