出版社:American Society for Biochemistry and Molecular Biology
摘要:A description is presented of the structural characterization of the normal unsaturated fatty acids of pig brain sphingolipids. The acids were isolated with the use of silver nitrate-impregnated silica gel and gas-liquid chromatography, and the positions of the double bonds were determined by a simplified ozonolysis procedure. In this method, the methyl esters were treated consecutively with ozone, performic acid, and diazomethane. Gas-liquid chromatography with a temperature program permitted analysis of the degradation products without preliminary separation of the mono- and dicarboxylic acids. Twenty-seven chemically-defined unsaturated acids were found, 25 of which have not been previously reported. These included the odd- and even-numbered monoenoic acids 22–26 carbon atoms long, as well as C24, C25, and C26 dienes. Each acid consisted of 2–4 positional isomers, which appear to have been derived from oleic, palmitoleic, linoleic, or an odd-numbered acid by chain elongation. Some of the acids appear to have been derived also by a 1-carbon degradation reaction from the longer homologue. Small amounts of trienoic acids were also found.