GAMMA-TOCOPHEROL DETOXIFICATION OF NITROGEN-DIOXIDE - SUPERIORITY TO ALPHA-TOCOPHEROL
GAMMA-TOCOPHEROL DETOXIFICATION OF NITROGEN-DIOXIDE - SUPERIORITY TO ALPHA-TOCOPHEROL
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DOI：
10.1073/pnas.90.5.1771
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发表时间：
1993-03-01
影响因子：
11.1
通讯作者：
MORDAN, LJ
中科院分区：
文献类型：
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作者：
COONEY, RV;FRANKE, AA;MORDAN, LJ
在维生素E组中，α-生育酚通常被认为是具有最高维生素生物活性的最有效的抗氧化剂，然而γ-生育酚由许多植物产生的量更大，并且是美国饮食中的主要生育酚。本报告描述了α-生育酚和γ-生育酚与二氧化氮（NO2）的化学反应性的根本差异，这导致α-生育酚而不是γ-生育酚形成亚硝化剂。一氧化氮（NO）是γ-生育酚与NO2反应的主要产物，而α-生育酚与NO2反应形成中间体生育氧化物类似物。有限的流行病学数据以及观察表明，在3-甲基胆蒽处理的C3 H/10 T1/2小鼠成纤维细胞中，γ-生育酚是一种比α-生育酚更有效的肿瘤转化抑制剂，这表明γ-生育酚具有生物学意义。后一种性质表明γ-生育酚在哺乳动物生物测定中的优越性和内源性NO产生在促进肿瘤转化中的作用。
In the vitamin E group, alpha-tocopherol is generally considered to be the most potent antioxidant with the highest vitamin bioactivity, yet gamma-tocopherol is produced in greater amounts by many plants and is the principal tocopherol in the United States diet. This report describes a fundamental difference in the chemical reactivities of alpha-tocopherol and gamma-tocopherol with nitrogen dioxide (NO2), which leads to the formation of a nitrosating agent from alpha-tocopherol, but not from gamma-tocopherol. Nitric oxide (NO) is a major product of the reaction of gamma-tocopherol with NO2, while alpha-tocopherol reacts with NO2 to form an intermediate tocopheroxide analogue. The biological significance of gamma-tocopherol is suggested by limited epidemiological data as well as the observation that it is a more potent inhibitor than alpha-tocopherol of neoplastic transformation during the postinitiation phase in 3-methylcholanthrene-treated C3H/10T1/2 murine fibroblasts. This latter property suggests the superiority of gamma-tocopherol in a mammalian biological assay and a role for endogenous NO production in promotion of neoplastic transformation.