THE UNUSUAL OCCURRENCE OF 14-METHYLHEXADECANOIC ACID IN PINACEAE SEEDOILS AMONG PLANTS

14-Methylhexadecanoic (14-MHD) acid has been identified in a sample of pine seed oil (Pinus contorta) by gas-liquid chromatography-mass spec trometry of its picolinyl ester derivative. Its identification (throug h its equivalent chain length) and its distribution in four conifer fa milies have been checked. It occurred only in Pinaceae, where it was f ound in 72 species belonging to the genera Pinus, Abies, Cedrus, Tsuga , Pseudotsuga, Larix, and Picea, in the range 0.02-1.15%. 14-MHD acid could not be detected in the lipids of Taxaceae (Taxus baccata), Cupre ssaceae (Juniperus communis), or Taxodiaceae (Sciadopytis verticillata ), even after a 10-fold concentration of the saturated acid fraction i solated by argentation thin-layer chromatography. It is concluded that Pinaceae along with Ginkgo biloba seed lipids, are major exceptions i n the plant kingdom with regard to 14-MHD acid, which otherwise occurs almost exclusively in lipids of animals and microorganisms. The biosy nthesis and metabolic role of 14-MHD acid, which otherwise also occur in wood and leaf lipids, remain unknown.