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Effects of sodium glycocholate and sodium taurocholate on the mixed micelles of bile salts and nonionic surfactant
Author(s) -
Asano H.,
Izumi C.,
Sano Y.,
Tabata Y.,
Ueno M.
Publication year - 1993
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02641005
Subject(s) - micelle , chemistry , mole fraction , pyrene , critical micelle concentration , pulmonary surfactant , aqueous solution , chromatography , ether , organic chemistry , biochemistry
Effects of sodium glycocholate (NaGC) and sodium taurocholate (NaTC) on the mixed micelles for two systems consisting of NaGC‐octaoxyethylene glycol mono n ‐decyl ether (C 10 E 8 ) and NaTC‐C 10 E 8 have been studied as a function of the mixed micelles’ compositions, polarities of the micelles’ interior and mean aggregation numbers. The compositions of the mixed micelles are calculated from critical micelle concentration (CMC) data by using excess thermodynamic quantities. The polarities and mean aggregation numbers are determined from pyrene fluorescence in the mixed micelles. Both mixed systems were nonideal, and the mole fraction of NaGC or NaTC in a mixed micelle near the CMC was less than that in the aqueous mixed solution. However, the mixed micelle of the NaTC‐C 10 E 8 system contained more bile salt molecules than that of the NaGC‐C 10 E 8 system because of a good miscibility of NaTC and C 10 E 8 molecules. The pyrene fluorescence results suggested that the mixed micelles changed from C 10 E 8 ‐rich micelles to NaGC‐ or NaTC‐rich micelles, and mean aggregation numbers of the mixed micelles decreased abruptly with increasing mole fraction of bile salts. In the low mole fraction range of bile salts, however, both the polarities and the mean aggregation numbers for the NaTC‐C 10 E 8 system are lower than those for the NaGC‐C 10 E 8 system because of the high mole fraction of NaTC in a mixed micelle, and also because of the different effect of the conjugated group between NaTC and NaGC molecules in the mixed micelles.