文献类型：期刊文献

英文题名：Shift of acid-base equilibrium of curcumin in its complexes with gemini surfactant hexamethylene-1,6-bis-(dodecyldimethyl ammonium bromide)

作者：Ke, Dan[1];Wu, Yue[1];Wang, Xiaoyong[1]

机构：[1]E China Univ Sci & Technol, Sch Chem & Mol Engn, Shanghai 200237, Peoples R China

年份：2014

卷号：443

起止页码：481

外文期刊名：COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS

收录：;EI(收录号：20140117161274);WOS:【SCI-EXPANDED(收录号:WOS:000342501300066)】；

基金：This work is supported by the National Natural Science Foundation of China (Grant 21173081), the Natural Science Foundation of Shanghai (Grant 11ZR1408600), and the Fundamental Research Funds for the Central Universities (Grant WK1213003).

语种：英文

外文关键词：Gemini surfactant; Curcumin; Acid-base equilibrium; Absorption; Fluorescence

摘要：Surfactant micelles are suitable carriers for solubilizing and stabilizing curcumin that is a natural polyphenolic compound with many biological and pharmacological activities but suffers poor bioavailability. In this paper, the acid-base equilibrium of curcumin (Cur(0) = Cur(-) + H+) has been studied in surfactant concentration dependent complexes of curcumin with gemini surfactant hexamethylene-1,6-bis(dodecyldimethyl ammonium bromide) (12-6-12). The absorption and fluorescence spectra of curcumin show that Cur- electrostatically binds with cationic 12-6-12 monomer to form curcumin/monomer complexes, whereas Cur(0) and Cur- are located in the palisade layer of 12-6-12 aggregates with different positions in curcumin/premicelle and curcumin/micelle complexes. The increase of surfactant concentration often leads to the right-shift of acid-base equilibrium of curcumin and higher amount of anionic Cur(-), as shown in the fluorescence spectra, pK(a1) and [Cur(-)]/[Cur(0)] of curcumin. By contrast, the added salt is found to be beneficial for curcumin to shift the acid-base equilibrium to the left side and keep in neutral Cur(0). (C) 2013 Elsevier B.V. All rights reserved.