Stability of trianionic curcumin enhanced by gemini alkyl O-Glucosides and alkyl trimethyl ammonium halides mixed micelles

Improved capability to inhibit degradation of trianionic curcumin has been realized in this study. The interaction between trianionic curcumin (Cur 3− ) and gemini dodecyl or tetradecyl O -glucoside micelles , tetradecyltrimethylammonium chloride (TTAC) or hexadecyltrimethylammonium bromide (CTAB) micelles as well as gemini alkyl O -glucosides (AGs)/alkyl trimethyl ammonium halides mixed micelles have been characterized. It is demonstrated that Cur 3− cannot be incorporated into gemini AGs micelles since the lack of electrostatic attraction and degraded as rapidly as in aqueous phase. Cur 3− tend to reside at palisade layer − water interface of TTAC or CTAB micelles due to the strong electrostatic interaction while moderate electrostatic interaction allows Cur 3− to locate more deeply in the palisade layer of mixed micelles. Additionally, mixed micelles tend to form a more compact and hydrophobic palisade layer than pure TTAC and CTAB ones. These factors bring about enhanced fluorescence intensity and blue − shift of emission maxima, improved fluorescence anisotropy and quantum yield, as well as reduced decay rate of Cur 3− in mixed micelles than in pure TTAC and CTAB ones.