The potent antioxidant α-tocopherol is known to trap two hydroxyl radicals leading to the formation of the experimentally observed α-tocopherylquinone product. Based on double-hybrid density functional theory calculations, we propose for the first time, a reaction mechanism for the conversion of α-tocopherol to α-tocopherylquinone. We find that a water-catalysed ring-opening reaction plays a key role in this conversion. The water catalysts act as proton shuttles facilitating the proton transfers and reducing the ring strain in the cyclic transition structures. On the basis of the proposed reaction mechanism, we proceed to design an antioxidant with potentially enhanced antioxidant properties.

已知有效的抗氧化剂α-生育酚会捕获两个羟基自由基，从而导致实验观察到的α-生育酚醌产物的形成。基于双杂化密度泛函理论计算，我们首次提出了一种将α-生育酚转化为α-生育酚醌的反应机理。我们发现水催化的开环反应在这种转化中起关键作用。水催化剂起质子穿梭的作用，促进质子转移并减少环状过渡结构中的环应变。在提出的反应机理的基础上，我们着手设计一种具有潜在增强的抗氧化剂性能的抗氧化剂。