Association of Catechin Molecules in Water: Quantitative Binding Study and Complex Structure Analysis
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- 作者：Tomomi Ujihara ; Nobuyuki Hayashi
- 刊名：Journal of Natural Products
- 出版年：2016
- 出版时间：January 22, 2016
- 年：2016
- 卷：79
- 期：1
- 页码：66-73
- 全文大小：626K
- ISSN：1520-6025
文摘
Associations between catechin molecules were investigated by 1H NMR titration experiments. Eight green tea catechins formed self-assembled dimers in water, and gallate-type catechins had a greater tendency to self-associate than non-gallate-type catechins. All eight catechins also associated as 1:1 heterodimer complexes. Investigation of complex formation of epigallocatechin-3-O-gallate (EGCg) and epigallocatechin (EGC) with the other catechins showed that the affinity between EGCg and 2,3-trans-gallate-type catechins was remarkably high, and the binding affinity of EGCg for ECg was also rather strong. In contrast, the non-gallate-type catechin EGC exhibited generally low binding affinity for other catechins. Structural analyses of the complexes by ROESY experiments and density functional theory calculations demonstrated that the higher binding abilities of gallate-type catechins are due to providing multiple intermolecular interactions that remain effective in an aqueous environment, such as aromatic/aromatic or CH/π interactions.