Marine lipids
Evaluation of a porous graphitic carbon
phase for semi-preparative liquid
chromatography of unsaturated fatty acids
C. Viron (1-2) , M. Lafosse
(1) , A. Saunois (2) , P. André
(2)
(1) Université d'Orléans, institut de chimie organique et analytique, UPRES-A 6005,
45067 Orléans Cedex 2, France
(2) Parfums Christian Dior, laboratoire substances naturelles,
45804 Saint-Jean-de-Braye Cedex, France
Marine algae contain compounds of potential interest in the cosmetic
and pharmaceutical industries.
Biological activity was found in an alcoholic extract obtained from a
microalga. After fractionation on silica gel, the active lipid fraction
contained fatty acids. To study their influence on this activity, pure
fatty acids were needed but not all are commercially available.
The aim of this work was to isolate the unavailable fatty acids and
determine their structure.
This fatty acid isolation was performed by HPLC on the fatty acid
methyl ester (FAMEs) derivatives. Silver liquid chromatography, reverse
phase liquid chromatography, and liquid chromatography on porous
graphitic carbon were compared for their separation efficiency and their
complementarity.
Preparative HPLC on porous graphitic carbon was finally chosen for its
selectivity and its capacity due to a better solubility of FAMEs in the
organic mobile phase (such as dichloromethane, methanol...). Purity
control of each fraction was carried out by silver liquid chromatography.
Identification of fractions was performed by gas chromatography linked
to an electron impact mass spectrometer. Different derivatives were
compared, but the 4,4-dimethyloxazoline derivatives (DMOX) seemed
to be the most effective to determine the alkyl chain length, the number
and the position of double bonds.
28