BISHOMOPINOLENIC (7,11,14-20 3) ACID IN PINACEAE SEED OILS/

Bishomopinolenic (7,11,14-20:3; BHP) acid has been identified in a sam ple of pine (Pinus contorla) seed oil by gas-liquid chromatography-mas s spectrometry of its 4,4-dimethyloxazoline and picolinyl ester deriva tives. Neither 20:3n-6 nor 18:3n-6 acids could be detected. The distri bution of BHP acid in the seed oils of four conifer families has been established. It only occurred in Pinaceae (Pinus, Abies, Cedrus, Tsuga , Pseudotsuga, Larix, and Picea; 72 species analyzed), where it could reach 0.7% of total fatty acids. It could not be detected in Taxaceae (Taxus baccata), Cupressaceae (Juniperus communis), or Taxodiaceae (Sc iadopytis verticillata) seed lipids. It is assumed that BHP acid is th e elongation product of pinolenic (5,9,12-18:3) acid, and that, at mos t, 3% of pinolenic acid is elongated to BHP acid. Consequently, the De lta 5-desaturation would not necessarily be a final step in the biosyn thesis of unsaturated polymethylene-interrupted fatty acids in Pinacea e seeds. Moreover, conifer seeds appear devoid oi the Delta 6-desatura se.