用紫外-可见(UV-Vis)吸收光谱和1H核磁共振(NMR)谱研究了茶多酚类衍生物表没食子儿茶素没食子酸酯(EGCG)与Zn(Ⅱ)离子的相互作用,并用密度泛函理论(DFT)计算了EGCG与Zn(Ⅱ)离子络合前后的空间结构及其紫外和核磁共振谱.实验与理论研究结果表明:EGCG主要构象是其芳香B环以e键(平伏键)及芳香D环以a键(直立键)形式共同与C环链接.EGCG通过其芳香D环上酚羟基与Zn(11)离子相互作用,生成稳定的Zn(Ⅱ)与EGCG摩尔比为1:1的Zn(Ⅱ)-EGCG四面体络合物.
The interaction between the tea polyphenols derivative (-)-epigallocatechin-3-gallate (EGCG) and Zn(Ⅱ) was investigated by ultraviolet visible (UV-Vis) spectroscopy and liquid-state 1H nuclear magnetic resonance (NMR). In addition, density functional theory (DFT)-based UV and chemical shifts were calculated to view insight into the complex structure and property. The main conformer of EGCG is an aromatic B-ring in an e-bond (equatorial bond) and an aromatic D-ring in an a-bond (axial bond) and these are linked to the C-ring. In addition, the Zn(Ⅱ) ion can coordinate with the phenolic hydroxyl groups in the D-ring and form a steady tetrahedral Zn(Ⅱ)-EGCG complex in a 1:1 molar ratio.