The CMC-like behaviour of bile salts as probed by photoexcited Rose Bengal

Abstract

The onset of the aggregation process in aqueous bile salt (BS) solutions remains a debated question. This study aimed at investigating this point through the detection of BS monomers and small aggregates using the dye Rose Bengal. Results showed that a few small BS aggregates led to a red shift of the absorption spectrum, while the BS monomer reacted with the photo-induced semi-oxidized dye and decreased its decay rate constant. The dye was dissolved in aqueous solution (10 mmol dm -3 NaOH) of sodium cholate (NaC), deoxycholate (NaDC), chenodoxycholate (NaCDC), dehydrocholate (NaDHC), glycocholate (NaGC) glycodeoxycholate (NaGDC), taurocholate (NaTC), taurodeoxycholate (NaTDC) and the zwitterionic analogue of sodium cholate called CHAPS. BS aggregates were detected at concentrations well below the concentration above which any added bile salt molecules

Conductivity and fluorescence studies on the micellization properties of sodium cholate and sodium deoxycholate in aqueous medium at different temperatures: Effect of selected amino acids

“…Aggregation of bile salts is responsible for their important physiological functions; for example, they often act as an emulsifier or solubilizing agents for hydrophobic dietary lipids in the intestine or as gallstone solubilizing agents in clinical medicine [4][5][6][7]. Therefore, different aspects of the aggregation process of bile salts in aqueous medium form a major topic of investigation by using various experimental [8][9][10][11][12][13] and computational techniques [14][15][16]. Apart from bile salts, phospholipids another important class of bio-surfactants (L-a-dimyristoylphosphatidycholine (DMPC), L-a-dipalmitoylphosphatidycholine (DPPC), and L-a-dilauroylphosphatidylethanolamine) have also been explored in mixed monomeric and dimeric cationic surfactant solutions [17,18] with the help of surface tension and fluorescence quenching measurements.…”

Thermodynamic Characterization of 3-[(3-Cholamidopropyl)-dimethylammonium]-1-propanesulfonate (CHAPS) Micellization Using Isothermal Titration Calorimetry: Temperature, Salt, and pH Dependence

“…20−25 It seems that aggregation of bile salt derivatives proceeds stepwise over a broad concentration range and with a great portion of polydispersity. It is why Seret and Bahri 24 suggested that, instead of critical micelle concentration, cmc, usually used to describe the micellization process, the concept of micellar dissociation concentration, defined as a concentration below which any dilution leads to disruption of the aggregates, should be applied. The efficiency of protein stabilization is highly related to the surfactant concentration.…”

Luminescent Sodium Deoxycholate Ionogel Induced by Eu3+ in Ethylammonium Nitrate

“…Their respective structures include a polar hydrophilic surface, a nonpolar hydrophobic surface, and a short hydrophilic tail. 17 BSs are natural anionic surfactants that can self-assemble in aqueous media to form supramolecular structures such as micelles, 18 hydrogels, 19 and liquid crystals. 20 Among them, the hydrogels based on sodium lithocholate or deoxycholate (NaDC) can be formed under appropriate pH conditions.…”

“…Their respective structures include a polar hydrophilic surface, a nonpolar hydrophobic surface, and a short hydrophilic tail . BSs are natural anionic surfactants that can self-assemble in aqueous media to form supramolecular structures such as micelles, hydrogels, and liquid crystals . Among them, the hydrogels based on sodium lithocholate or deoxycholate (NaDC) can be formed under appropriate pH conditions. ,, Adding metal ions to BS systems, however, can improve gel performance because the introduced metal ions not only triggers the self-assembly process but also imparts unique properties to gels such as conductivity and luminescence .…”