Dynamic behavior of plant polyphenols in biological membranes

用溶液核磁共振技术研究了茶儿茶素没食子酸酯和表没食子儿茶素没食子酸酯与各向同性双胞模型脂膜的相互作用。1H核磁共振测量表明，儿茶素与双环相互作用后，心电和EGCG的B环和没食子酰基发生了明显的位移，其质子T_1驰豫时间缩短。这些结果表明，B环和没食子酸基在这种相互作用中起着重要作用。核奥弗豪瑟效应光谱实验证明，B环和没食子酰基位于磷脂三甲基铵基团中的γ-H附近。在这些发现的基础上，我们认为心电和EGCG通过胆碱部分与脂膜表面相互作用。

Interaction between tea catechins, such as epicatechin gallate (ECg) and epigallocatechin gallate (EGCg), and isotropic bicelle model lipid membranes was investigated by solution NMR techniques. ^1HNMR measurements provided signals from the B-ring and the galloyl moiety in ECg and EGCg that were obviously shifted, and whose proton T_1 relaxation times were shortened upon interaction of the catechins with the bicelles. These results indicate that the B-ring and the galloyl moiety play an important role in this interaction. Nuclear Overhauser effect spectrometry experiments demonstrated that the B-ring and the galloyl moiety are located near the γ-H in the phospholipid trimethylammonium group. On the basis of these findings, we propose that ECg and EGCg interact with the surface of lipid membranes via the choline moiety.