Gas Chromatographic Analysis of Long-Chain Fatty Acids in Gangliosides

Abstract

BRAIN gangliosides are complex, aggregate, water-soluble lipids with an apparent molecular weight of about 220,000 in aqueous solution. The constituent building blocks have been identified as N-acetyl neuraminic acid, N-acetyl galactosamine, galactose, glucose, sphingosine and a long-chain fatty acid^1,2. The exact structure of the complex unit has, however, not been elucidated. It has been possible to separate various gangliosides by repeated crystallization^2,3 or by chromatography^3–5 into closely related fractions the compositions of which are as yet uncertain. Klenk originally identified the fatty acid isolated from brain gangliosides as stearic acid. In view of the fact that Kishimoto and Radin⁶ were able to demonstrate a considerable variation in the fatty acid moiety of cerebrosides, a glycolipid very closely related to the gangliosides, it was considered that the original findings of stearic acid only in the gangliosides should be re-investigated by means of the more advanced techniques now available.