Cooperative Binding and Stabilization of the Medicinal Pigment Curcumin by Diamide Linked 纬-Cyclodextrin Dimers: A Spectroscopic Characterization

详细信息    查看全文

• 作者：Takaaki Harada ; Duc-Truc Pham ; Mandy H. M. Leung ; Huy Tien Ngo ; Stephen F. Lincoln ; Christopher J. Easton ; Tak W. Kee
• 刊名：Journal of Physical Chemistry B
• 出版年：2011
• 出版时间：February 10, 2011
• 年：2011
• 卷：115
• 期：5
• 页码：1268-1274
• 全文大小：918K
• 年卷期：v.115,no.5(February 10, 2011)
• ISSN：1520-5207

文摘

Diamide linked 纬-cyclodextrin (纬-CD) dimers are used to capture curcumin and suppress its decomposition in water. In this study, succinamide and urea linked 纬-CD dimers joined through the C6^A carbon on each 纬-CD are used. The 纬-CD dimers, 66纬CD₂su and 66纬CD₂ur, show a remarkable ability to suppress the decomposition of curcumin and extend its half-life from less than 30 min to greater than 16 h. The 1:1 association of curcumin with 66纬CD₂su and 66纬CD₂ur has high stability constants of 8.7 脳 10⁶ M^鈭? and 2.0 脳 10⁶ M^鈭?, respectively. In addition, 2D ¹H NOESY NMR results show specific hydrogen interactions in the association of curcumin with 66纬CD₂su and 66纬CD₂ur, consistent with the cooperative binding of curcumin by both 纬-CD annuli of 66纬CD₂su and 66纬CD₂ur. The interactions between curcumin in the linked 纬-CD dimers and surfactant micelles were studied using fluorescence spectroscopy. While linked 纬-CD dimer-bound curcumin has a negligible fluorescence quantum yield, a significant increase in fluorescence intensity (桅_fl > 2%) in the presence of micelles suggests that curcumin is delivered to the micelle. The overall results indicate that the diamide linked 纬-CD dimers are highly promising systems for curcumin delivery in vivo due to effective curcumin stabilization.