FRACTIONATION OF LIPID COMPONENTS ISOLATED FROM ENDOTOXIN AND THEIR CHEMICAL AND BIOLOGICAL PROPERTIES

Abstract

Neutral, polar-I, and polar–II lipid fractions were separated, with organic solvents and silica gel column chromatography, from lipid material obtained by the acid hydrolysis of Salmonella typhosa, strain 0–901 endotoxins. The neutral lipids were mainly composed of fatty acids; the polar-I lipids of fatty acids and glucosamine, and the polar–II lipids of fatty acids, glucosamine, and phosphorylethanolamine. The lethal, pyrogenic, and interferon-inducing activities were found in polar–I and polar–II lipid fractions. The polar-II lipids were further fractionated by silica gel chromatography and 13 subfractions were obtained. Among these subfractions, the lethal activity was found in subfractions 1,2,3,4,5 and 7, being especially high in subfractions 2 and 3. The pyrogenic and interferon-inducing activities were in subfractions 1 through 5. Fatty acids, glucosamine and phosphorylethanolamine were in all subfractions. Contents of lauric acid, myristic acid and palmitic acid were comparably high in subfractions 1,2, and 3.