Stoyanovsky D A, Kagan V E, Packer L
Institute of Physiology, Bulgarian Academy of Sciences, Sofia.
Biochem Biophys Res Commun. 1989 Apr 28;160(2):834-8. doi: 10.1016/0006-291x(89)92509-6.
Tocopherols (vitamin E) located in the hydrophobic domains of biological membranes act as chain breaking antioxidants preventing the propagation of free radical reactions of lipid peroxidation. The naturally occurring form, d-alpha tocopherol is an exquisite molecule in that it is intercalated in the membrane in such a way that the hydrophobic tail anchors the molecule positioning the chromanol ring containing the hydroxyl group, which is the essence of its antioxidant function, at the polar hydrocarbon interface of phospholipid membranes. The interaction of this group with water soluble substances is not very well understood. In the present study, an investigation was made of the interaction of ascorbate and ferrous ions (Fe+2) initiators of lipid peroxidation with alpha tocopherol. The results show that tocopherol increases membrane associated iron. The formation of a tocopherol iron complex in the presence of phospholipid liposomes and ascorbate in its reduced form is indicated. These results suggest a new way in which tocopherols act to inhibit lipid peroxidation.
位于生物膜疏水区域的生育酚（维生素E）作为链断裂抗氧化剂，可防止脂质过氧化的自由基反应的传播。天然存在的形式，即d-α生育酚，是一种精致的分子，它以这样一种方式插入膜中：疏水尾部锚定分子，将含有羟基的色满环定位在磷脂膜的极性烃界面处，而羟基是其抗氧化功能的关键。该基团与水溶性物质的相互作用尚未得到很好的理解。在本研究中，对脂质过氧化引发剂抗坏血酸盐和亚铁离子（Fe²⁺）与α生育酚的相互作用进行了研究。结果表明，生育酚会增加与膜相关的铁。表明在磷脂脂质体和还原形式的抗坏血酸盐存在下形成了生育酚铁复合物。这些结果提示了生育酚抑制脂质过氧化作用的一种新方式。
