title: Alteration of physical, chemical, and biological properties of endotoxin by treatment with mild alkali.
abstract: Treatment with alkali is one of several methods for removing fatty acids from bacterial endotoxins and, in the process, detoxifying the material. Saponification of fatty acid esters is the major detectable chemical change produced by alkali; however, kinetic studies of mild alkaline hydrolysis of endotoxin failed to correlate rates of detoxification with rates of loss of ketodeoxyoctonates, heptose, O-acetyl groups, or fatty acid esters. The alterations occurring during the critical stages of hydrolysis apparently changed the essential chemical conformation of endotoxic particles before cleavage of a significant amount of material took place. The rates of both saponification and detoxification were markedly increased by carrying out the reaction in media of ethyl alcohol or dimethylsulfoxide instead of water.
mesh_terms: D000468:Alkalies; D001647:Bile Acids and Salts; D055598:Chemical Phenomena; D002621:Chemistry; D004121:Dimethyl Sulfoxide; D004731:Endotoxins / Q000032:analysis; D004926:Escherichia coli; D000431:Ethanol; D005227:Fatty Acids; D006898:Hydroxylamines; D012475:Salmonella; D012972:Sodium Hydroxide; D014461:Ultracentrifugation
chemical_list: D000468:Alkalies; D001647:Bile Acids and Salts; D004731:Endotoxins; D005227:Fatty Acids; D006898:Hydroxylamines; D000431:Ethanol; D012972:Sodium Hydroxide; D004121:Dimethyl Sulfoxide