Studies on the lipid components of endotoxin. II. Chemical analyses and biological properties of neutral, polar-I and polar-II subfractions.
Lipid components obtained from Salmonella typhosa O-901 endotoxin by acid hydrolysis were separated into neutral, polar-I and polar-II lipid fractions by silica gel column chromatography. These lipids were further separated by silica gel column and/or thin-layer chromatography. The subfractions were analyzed by thin-layer chromatography, gas chromatography and infrared spectrophotometry. Seven subfractions obtained from the neutral lipid fraction contained lauric, myristic, palmitic, 3-OH-myristic acid, artificial products of 3-OH-myristic acid, or a small amount of two unidentified fatty acids. These fatty acids and glucosamine were commonly detected in six subfractions obtained from the polar-I lipid fraction. Fatty acids, glucosamine, and O-phosphorylethanolamine were detected in all of the 13 subfractions obtained from the polar-II lipid fraction. Chick embryo lethal activity, rabbit pyrogenicity and in vitro interferon inducing activity were found in three polar-I lipid subfractions and five polar-II lipid subfractions, but not in neutral lipids. The activities were highest in a polar-II lipid subfraction which contained smaller amounts of O-phosphorylethanolamine and glucosamine than the other subfractions. However, no particular chemical constituent(s) related to the biological activities could be found. Prolonged acid hydrolysis of the polar-II lipids gave rise to neutral and polar-I lipids. Chemical and biological aspects of the lipid constituents of endotoxin are discussed.
D000818:Animals; D002460:Cell Line; D002642:Chick Embryo; D004731:Endotoxins / Q000032:analysis*; D005227:Fatty Acids / Q000032:analysis; D005334:Fever / Q000139:chemically induced; D005944:Glucosamine / Q000032:analysis; D007372:Interferons / Q000096:biosynthesis; D007928:Lethal Dose 50; D008055:Lipids / Q000032:analysis* / Q000494:pharmacology / Q000633:toxicity; D011817:Rabbits; D012485:Salmonella typhi / Q000032:analysis*
D004731:Endotoxins; D005227:Fatty Acids; D008055:Lipids; D007372:Interferons; D005944:Glucosamine