Determination of ganglioside non-hydroxy fatty acid and long chain base by analysis of perbenzoylated derivatives.

The non-hydroxy fatty acid and long chain base compositions from as little as 2.7 nmol of ganglioside were ascertained from perbenzoylated ganglioside derivatives. Non-hydroxy fatty acids were determined by mild alkaline methanolysis of the derivatives, followed by gas-liquid chromatography (GLC) of the methyl esters. N-acyl and N-benzoyl "gangliosides" that were generated by the methanolysis were hydrolyzed by a standard procedure that utilized aqueous acetonitrile-HCl, followed by high performance liquid chromatography (HPLC) determination of the biphenylcarbonyl derivatives with ultraviolet (UV) detection at 280 nm. A critical aspect of this procedure is a modified workup for the isolation of the biphenylcarbonyl derivatives which eliminates by-products that otherwise interfere with their separation by HPLC, especially when high sensitivity is required.