Purification and gas chromatographic-mass spectrometric characterization of non-methylene interrupted fatty acid incorporated in rat liver

Abstract

A C20 non-methylene interrupted trienoic acid detected in the liver of rat fed with a pine ( Pinus koraiensis) seed oil diet was purified by two-step argentation thin-layer chromatography (AgTLC) and characterized by gas chromatography-mass spectrometry (GC-MS). First, a C20 methyl trienoate fraction was obtained from fatty acid methyl esters prepared from rat liver by 5% AgTLC developed with petroleum ether-diethyl ether-acetic acid (70:20:2, v/v) as a solvent system. The fraction was then subjected to AgTLC developed with benzene-acetone-diethyl ether-acetic acid (65:15:15:5, v/v) which could separate non-methylene interrupted fatty acids (NMIFA) from usual MIFAs. The purified C20 NMIFA was partially hydrogenated, and the resulting three kinds of the C20 monoenoate were analyzed by GC-MS after conversion to their dimethyl disulfide (DMDS) adducts. The results revealed that the original C20 non-methylene interrupted trienoic acid detected in the liver of rats fed with a pine seed oil diet was Δ-5,11,14/20:3, a minor component of pine seed oil.