Lipid composition of beef brain, beef liver, and the sea anemone: Two approaches to quantitative fractionation of complex lipid mixtures

Abstract

Two new schemes for fractionation of complex lipid mixtures are presented. Their use for the study of lipids of beef brain, beef liver, and the sea anemone are described. Apparatus and techniques for working in an inert atmosphere, evaporation of solutions in the cold under nitrogen, use of infrared spectroscopy for examination of lipids and their hydrolysis products, preparation and clution of diethylaminoethyl (DEAE) cellulose and silicic acid‐silicate columns and general column combinations that can be used to fractionate complex lipid mixtures are considered in detail. The first scheme, employing DEAE cellulose columns followed by thin layer and paper chromatographic examination of the fractions, was applied to liver lipids. The many components, some of them new lipids not previously detected, are clearly seen with this technique but are not seen when paper or thin layer chromatography alone or silicic acid chromatography are used. The second scheme employing DEAE for initial fractionation, followed by complete separation on silicic acid and silicic acid‐silicate columns, was applied to lipids of the sea anemone and beef brain. Typical lecithin and phosphatidyl ethanolamine were isolated, but sphingomyelin was not found. A new sphingolipid, ceramide aminoethylphosphonate, with a free amino group and a direct carbon to phosphorus bond was isolated and characterized. The methods used for quantitative isolation, the infrared spectra, and the amounts of cholesterol, ceramide, cerebroside, galactosylglyceride, sulfatide, sphingomyelin, lecithin, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, triphosphoinositide, phosphatidic acid, cardiolipin, and ganglioside of beef brain are presented. Finally, the types of lipid‐nonlipid interactions disclosed by column chromatography and their potential application to biological problems are discussed.