Enhancing effect of nonionic surfactant on the inactivation of lipopolysaccharide by steam-heat treatment II.
n-alkylpolyoxyethylene surfactants (CnH2n+1O(CH2CH2O)mH; CnEm) showed a strong enhancing effect on the inactivation of lipopolysaccharide (LPS) by heat treatment over a wide range of temperatures. The effect of CnE8 (n = 10-16) was observed above the critical micelle concentration (CMC) and above the cloud point, and was influenced by the length of the alkyl chains. The efficacy of the surfactants was in the order C10E8 < C12E8, C16E8 < C14E8. However, the hydrophilic moiety seemed to have no influence. An 80-95% solution of n-butanol showed a similar effect, indicating that LPS was more effectively inactivated in the oily phase of the surfactants than in water. The effect of surfactant on the hydrodynamic diameter of LPS was the same before and after steam-heat treatment for 20 minutes at 121 degrees C. Each surfactant disaggregated LPS without alteration of the activity of LPS before the heat treatment. We consider that the surfactants interact with LPS in the region of lipid A in a manner that favors loss of the activities of LPS during heating.
Bamba
T
T
Pharmaceutical Research Center, Shiseido Company, Limited, Yokohama, Japan.
Matsui
R
R
Watabe
K
K
Mayumi
T
T
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004731:Endotoxins / Q000737:chemistry*; D005026:Ethylene Glycols / Q000737:chemistry / Q000494:pharmacology*; D006358:Hot Temperature; D008027:Light; D008033:Limulus Test; D008070:Lipopolysaccharides / Q000737:chemistry*; D012542:Scattering, Radiation; D013242:Sterilization; D013501:Surface-Active Agents / Q000737:chemistry / Q000494:pharmacology*
D004731:Endotoxins; D005026:Ethylene Glycols; D008070:Lipopolysaccharides; D013501:Surface-Active Agents; C519924:octaethylene glycol monotetradecyl ether; C044101:endotoxin, Escherichia coli