(−)-Epigallocatechin gallate (EGCG), the main component of green tea extract, displays multiple biological activities. However, it cannot be used as a drug due to its low cellular absorption, instability and metabolic degradation. Therefore, there is a need to provide analogs that can overcome the limitations of EGCG. In this work, six synthetic analogs of EGCG sharing a common tetralindiol dibenzoate core were synthesized and fully characterized by 1H NMR, 13C NMR, HRMS and IR spectroscopies, and X-ray crystallography. These are (2R,3S)-1,2,3,4-tetrahydronaphthalene-2,3-diyl bis[3,4,5-tris(benzyloxy)benzoate], C66H56O10, and the analogous esters bis(3,4,5-trimethoxybenzoate), C30H32O10, bis(3,4,5-trifluorobenzoate), C24H14F6O4, bis[4-(benzyloxy)benzoate], C38H32O6, bis(4-methoxybenzoate), C26H24O6, and bis(2,4,6-trifluorobenzoate), C24H14F6O4. Structural analysis revealed that the molecular shapes of these dibenzoate esters of tetralindiol are significantly different from that of previously reported dimandelate esters or monobenzoate esters, as the acid moieties extend far from the bicyclic system without folding back over the tetralin fragment. Compounds with small fluorine substituents take a V-shape, whereas larger methoxy and benzyloxy groups determine the formation of an L-shape or a cavity. Intermolecular interactions are dominated by π–π stacking and C—H...π interactions involving the arene rings in the benzoate fragment and the arene ring in the tetrahydronaphthalene moiety. All six crystal structures are determined in centrosymmetric space groups (either P-1, P21/n, C2/c or I2/a).
(-)-表没食子儿茶素没食子酸酯(EGCG)是绿茶提取物的主要成分,具有多种生物活性。然而,由于其细胞吸收率低、不稳定性和代谢降解,它不能用作药物。因此,有必要提供能克服 EGCG 局限性的类似物。本研究合成了六种 EGCG 类似物,它们具有共同的四吲哚二苯甲酸酯核心,并通过 1H、13C、HRMS、IR 光谱和 X 射线晶体学对其进行了全面表征。它们是(2R,3S)-1,2,3,4-四氢萘-2,3-二基双[3,4,5-三(苄氧基)苯甲酸酯](C66H56O10)和类似酯双(3,4,5-三甲氧基苯甲酸酯)(C30H32O10)、双(3,4,5-三氟苯甲酸酯),C24H14F6O4;双[4-(苄氧基)苯甲酸酯],C38H32O6;双(4-甲氧基苯甲酸酯),C26H24O6;以及双(2,4,6-三氟苯甲酸酯),C24H14F6O4。结构分析表明,这些四氢萘二醇二苯甲酸酯的分子形状与之前报道的二扁桃酸酯或单苯甲酸酯有很大不同,因为酸分子远离双环系统,不会折回到四氢萘片段上。含少量氟取代基的化合物呈 V 形,而含较大甲氧基和苄氧基的化合物则会形成 L 形或空腔。分子间的相互作用主要是π-π堆积和涉及苯甲酸酯片段中的芳环和四氢萘分子中的芳环的C-H...π相互作用。所有六个晶体结构都是在中心对称空间群(P-1、P21/n、C2/c 或 I2/a)中确定的。