Journal of the American Oil Chemists' Society

, Volume 75, Issue 12, pp 1749–1755

A simple method of preparation of methyl trans-10,cis-12- and cis-9,trans-11-octadecadienoates from methyl linoleate

  • O. Berdeaux
  • L. Voinot
  • E. Angioni
  • P. Juanéda
  • J. L. Sébédio
Article

DOI: 10.1007/s11746-998-0327-x

Cite this article as:
Berdeaux, O., Voinot, L., Angioni, E. et al. J Amer Oil Chem Soc (1998) 75: 1749. doi:10.1007/s11746-998-0327-x

Abstract

Pure conjugated isomers of linoleic acid were prepared on a large scale by alkali-isomerization of purified methyl linoleate. The methyl esters of alkali-isomerized linoleic acid contained mainly the methyl cis-9,trans-11- and trans-10,cis-12-octadecadienoates (44 and 47%, respectively). These two isomers were then separated and purified by a series of low-temperature crystallizations from acetone. The isomeric purity obtained for the cis-9,trans-11-octadecadienoate isomer was >90% and that of the trans-10,cis-12-octadecadienoate isomer was 89 to 97%. The isolated yield of the two isomers corresponded to 18 and 25.7%, respectively, of the starting material. The structure of the two isomers was confirmed using partial hydrazine reduction, silver nitrate-thin-layer chromatography of the resulting monoenes and gas chromatography coupled with mass spectrometry of the 4,4-dimethyloxazoline derivatives. Fourier transform infrared spectroscopy of the monoenes gave the confirmation of the geometry of each double bond.

Key words

Conjugated linoleic acid (CLA) 4,4-dimethyloxazoline derivative GC-FTIR GC-MS hydrazine reduction isomerization linoleic acid low-temperature crystallization NMR silver nitrate-thin layer chromatography UV 

Copyright information

© AOCS Press 1998

Authors and Affiliations

  • O. Berdeaux
    • 1
  • L. Voinot
    • 1
  • E. Angioni
    • 1
  • P. Juanéda
    • 1
  • J. L. Sébédio
    • 1
  1. 1.INRAUnité de Nutrition LipidiqueDijon CedexFrance

Personalised recommendations