Occurrence of positional isomers of octadecenoic and hexadecenoic acids in human depot fat

• Main Authors: Jürgen Jacob, Gernot Grimmer
• Format: Article
• Language: English
• Published: Elsevier 1967-07-01
• Series: Journal of Lipid Research
• Subjects: man; adipose tissue; positional isomers; hexadecenoic and octadecenoic acids; oxidative cleavage; branched fatty acids
• Online Access: http://www.sciencedirect.com/science/article/pii/S0022227520395596

Positional isomers of hexadecenoic aud octadecenoic acids of human adipose tissue have been separated by gas-liquid chromatography and their amounts determined by oxidative cleavage (MnO4 and IO4). The following isomeric octadecenoic acids were present: 7-octadecenoic acid (0.4%), 8- (1.9%), 9- (73.0%), 10- (2.5%), 11- (19.0%) and 12- (3.2%). The hexadecenoic acids have also been shown to be a mixture of positional isomers, in which the cis-9-isomer predominates. 10-Hexadecenoic and 12-octadecenoic acids could conceivably be precursors of linoleic acid.The following branched fatty acids have also been determined in human depot fat: 13-methyltetradecanoic, 12-methyltetradecanoic, 14-methylpentadecanoic, 14-methylhexadecanoic, and 16-methylheptadecanoic acid. They were present in percentages of 0.02-0.6% and their identification rests solely on comparison of their gas-liquid chromatographic retention times with those of synthetic compounds.