Xia Yirong, Ni Wei, Wang Xintong, Wang Yanyan, Huang Ximing
School of Food and Chemical Engineering, Shaoyang University Shaoyang 422000 China
Beijing Aerospace Propulsion Institute Beijing 100076 China.
RSC Adv. 2022 Aug 1;12(33):21135-21144. doi: 10.1039/d2ra03692d. eCollection 2022 Jul 21.
The health benefits of drinking tea stem from it being rich in polyphenols and other physiologically-active substances. Thus, exploring the synergistic effect between polyphenols and a variety of physiologically-active substances can contribute to our understanding of how tea benefits health. In this work, we have studied the interactions between catechin and theanine, exploring the synergetic antioxidant mechanism of the two molecules. Electrochemical characterization results showed that the oxidation peak current of catechin decreased gradually with the concentration of theanine, which is due to theanine spontaneously binding to catechin through intermolecular hydrogen bonds and forming molecular clusters two hydrogen bonds. The binding constant is 4.75 at room temperature. The molecular clusters reduce the diffusion coefficient of catechin in solution, leading to the slow release of its antioxidant capacity (ability to effectively inhibit free radical oxidation reactions). Density functional theory calculations were also performed and verified the binding behavior. In identifying the synergistic effect between catechin and theanine on the antioxidant capacity of tea, this study adds to our understanding of the efficacy of tea polyphenols.
喝茶对健康有益源于其富含多酚和其他生理活性物质。因此，探索多酚与多种生理活性物质之间的协同效应有助于我们理解茶对健康有益的方式。在这项工作中，我们研究了儿茶素与茶氨酸之间的相互作用，探索了这两种分子的协同抗氧化机制。电化学表征结果表明，儿茶素的氧化峰电流随着茶氨酸浓度的增加而逐渐降低，这是由于茶氨酸通过分子间氢键自发地与儿茶素结合并形成分子簇——两个氢键。室温下的结合常数为4.75。分子簇降低了儿茶素在溶液中的扩散系数，导致其抗氧化能力（有效抑制自由基氧化反应的能力）缓慢释放。还进行了密度泛函理论计算并验证了这种结合行为。在确定儿茶素与茶氨酸对茶抗氧化能力的协同效应方面，本研究增进了我们对茶多酚功效的理解。
