Barclay L R, Bailey A M, Kong D
J Biol Chem. 1985 Dec 15;260(29):15809-14.
A comparison is made of the antioxidant activity of a water-soluble form of alpha-tocopherol complexed with bovine serum albumin (alpha-T X BSA) with that of micellar alpha-tocopherol and aqueous 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylate (Trolox) to inhibit autoxidation of linoleic acid in sodium dodecyl sulfate micelles. The peroxyl radical trapping ability of alpha-T X BSA compares favorably with that of alpha-tocopherol and Trolox, and all three can be used in quantitative measurements of the susceptibility of the micellar substrate to undergo autoxidation: the oxidizability, for reactions initiated in the micellar phase by di-tertbutylhyponitrite (DBHN) or in the aqueous phase by azobisamidinopropane hydrochloride (ABAP). alpha-Tocopherol and Trolox are also effective antioxidants to inhibit DBHN- or ABAP-initiated autoxidations of dilinoleoylphosphatidylcholine (DLPC) liposomes prepared as multilamellar or unilamellar bilayers characterized by 31P NMR spectra. The oxidizability of DLPC liposomes is determined by various combinations of water-soluble and lipid-soluble initiators and the antioxidants, alpha-tocopherol and Trolox. In contrast, alpha-T X BSA does not effectively trap peroxyl radicals when it is added after initiation of autoxidation in the lipid phase (DBHN) or in the aqueous phase (ABAP). The radical trapping ability of alpha-T X BSA becomes evident if it is mixed with the DLPC for some hours before initiation. This result is interpreted in terms of diffusion of alpha-tocopherol from the bound alpha-T X BSA form to the liposome before it exhibits antioxidant activity.
将与牛血清白蛋白复合的水溶性α-生育酚（α-T X BSA）的抗氧化活性与胶束态α-生育酚和6-羟基-2,5,7,8-四甲基色满-2-羧酸酯水溶液（Trolox）的抗氧化活性进行比较，以抑制十二烷基硫酸钠胶束中亚油酸的自氧化。α-T X BSA的过氧自由基捕获能力与α-生育酚和Trolox相比具有优势，并且这三种都可用于定量测量胶束底物发生自氧化的敏感性：对于由二叔丁基亚硝酸盐（DBHN）在胶束相中引发或由盐酸偶氮双脒丙烷（ABAP）在水相中引发的反应，其氧化能力。α-生育酚和Trolox也是有效的抗氧化剂，可抑制以31P NMR光谱表征的多层层状或单层层状双分子层形式制备的二油酰磷脂酰胆碱（DLPC）脂质体的DBHN或ABAP引发的自氧化。DLPC脂质体的氧化能力由水溶性和脂溶性引发剂以及抗氧化剂α-生育酚和Trolox的各种组合决定。相比之下，当在脂质相（DBHN）或水相（ABAP）中自氧化引发后添加α-T X BSA时，它不能有效地捕获过氧自由基。如果在引发前将α-T X BSA与DLPC混合数小时，其自由基捕获能力就会变得明显。该结果可解释为在α-生育酚表现出抗氧化活性之前，它从结合的α-T X BSA形式扩散到脂质体中。
