کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7595132 | 1492123 | 2015 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Improved solubility and stability of 7-hydroxy-4-methylcoumarin at different temperatures and pH values through complexation with sulfobutyl ether-β-cyclodextrin
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
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چکیده انگلیسی
The inclusion complex of 7-hydroxy-4-methylcoumarin (7H4MC) with sulfobutyl ether-β-cyclodextrin (SBE-β-CD) was investigated by means of UV-vis, circular dichroism and 1H NMR spectroscopy in phosphate buffer solutions at different temperatures and pH values. The stoichiometric ratio of the complexation was found to be 1:1 and the stability constants (KC) were estimated from phase solubility analysis. The thermodynamic parameters of standard Gibbs free energy change, ÎGo, enthalpy change, ÎHo, and entropy change, ÎSo, for the complexation process were obtained by using the van't Hoff equation and Gibbs-Helmholtz equation. The large negative ÎHo and the small negative or positive ÎSo (|ÎHo| > |TÎSo|) demonstrated that the inclusion interaction was an enthalpy-driven process. The positive signal of circular dichroism indicated that 7H4MC penetrated the cavity in such a way that the transition moment of the guest chromophore was parallel to the long axis of SBE-β-CD cavity. Moreover, the 1H NMR spectrum showed that the entire 7H4MC molecule, except the hydroxyl group, was included in the SBE-β-CD cavity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Food Chemistry - Volume 168, 1 February 2015, Pages 270-275
Journal: Food Chemistry - Volume 168, 1 February 2015, Pages 270-275
نویسندگان
Min Liu, Aiju Chen, Yong Wang, Chunmei Wang, Bingquan Wang, Dezhi Sun,