Chromatography of sphingolipids of human brain*

Abstract

Sphingolipids of the brain were prepared by solvent extraction of the tissue or from mixed brain extracts subjected to mild alkaline hydrolysis. Their components were separated on silicic-acid columns. Through use of a gradient elution with a number of chloroform-methanol mixtures and pure methanol, satisfactory fractions were obtained in an 8-hour period. The elution patterns were constant and the recoveries of hexose and alkali-stable phosphorus high. Combined chemical, infrared, and paper chromatographic techniques were used for analysis. Pure galactocerebrosides were isolated and in some instances further characterized by gas-liquid chromatography of their fatty acid derivatives. Preliminary results suggest that cerebrosides containing normal acids are eluted earlier from silicic-acid columns than those containing hydroxylated acid. A ceramide was detected in the brain from a patient with multiple sclerosis and significant amounts of glucocerebrosides in the brain of an old patient. Dihydrocerebroside-like fractions and other not characterized sphingosine derivatives were found in some instances. Pure sphingomyelins were isolated from small amounts of brain tissue.