Density functional theory (DFT) calculations were used to investigate the conformational landscape of catechin and one of its main glucoside derivative (catechin-3′ O- α −glucopyranoside), and to determine the corresponding antioxidant properties. These investigations were carried out in benzene and water using the SMD universal continuum solvation model. Both properties were found to be significantly affected. The structures are characterized in both solvents by strong intramolecular hydrogen bonds (IMHB). In an apolar environment, Hydrogen Atom Transfer (HAT) is by far favored whereas in water the Sequential Proton Loss Electron Transfer (SPLET) mechanism is strongly preferred. In benzene, the catechin fragment has the best antioxidant character (from 27 kJ/mole) whereas in polar surroundings, the glucoside derivative has a slightly better antiradical activity (from 5 kJ/mole). Our results confirm the key role of the 3′-OH and 4′-OH groups of the catechole ring in these properties.

中文翻译：

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儿茶素及其 3′O-α-葡萄糖苷的抗氧化特性：计算化学计算的见解

使用密度泛函理论 (DFT) 计算研究儿茶素及其主要葡萄糖苷衍生物之一（儿茶素-3′O-α-吡喃葡萄糖苷）的构象景观，并确定相应的抗氧化特性。这些研究是使用 SMD 通用连续介质溶剂化模型在苯和水中进行的。发现这两种属性均受到显着影响。两种溶剂中的结构均以强分子内氢键 (IMHB) 为特征。在非极性环境中，氢原子转移（HAT）机制是迄今为止最受青睐的，而在水中，顺序质子损失电子转移（SPLET）机制是强烈首选的。在苯中，儿茶素片段具有最佳的抗氧化特性（27 kJ/摩尔起），而在极性环境中，葡萄糖苷衍生物具有稍好的抗自由基活性（5 kJ/摩尔起）。我们的结果证实了儿茶酚环的 3′-OH 和 4′-OH 基团在这些特性中的关键作用。