BETA-CAROTENE - AN UNUSUAL TYPE OF LIPID ANTIOXIDANT
BETA-CAROTENE - AN UNUSUAL TYPE OF LIPID ANTIOXIDANT
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DOI：
10.1126/science.6710156
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发表时间：
1984-01-01
期刊：
影响因子：
56.9
通讯作者：
INGOLD, KU
中科院分区：
文献类型：
--
作者：
BURTON, GW;INGOLD, KU
本文综述了脂质过氧化作用的机制和抗氧化剂的作用方式。β-胡萝卜素是一种据称的抗癌剂，一些人认为它具有自由基捕获型的抗氧化作用。然而，这种行动缺乏明确的实验支持。新的体外实验表明，β-胡萝卜素属于以前未知的一类生物抗氧化剂。具体地说，它仅在氧分压显著低于150 ℃（正常空气中的氧压）时才表现出良好的自由基捕获抗氧化剂行为。这种低氧分压在生理条件下的大多数组织中发现。在较高的氧气压力下，β-胡萝卜素失去其抗氧化活性，并显示出自催化、促氧化作用，特别是在相对高的浓度下。其他含有许多共轭双键的化合物也可能表现出类似的氧压依赖性。
The mechanism of lipid peroxidation and the manner in which antioxidants function is reviewed. β-Carotene is a purported anticancer agent, which is believed by some to have antioxidant action of a radical-trapping type. However, definitive experimental support for such action has been lacking. New experiments in vitro show that β-carotene belongs to a previously unknown class of biological antioxidants. Specifically, it exhibits good radical-trapping antioxidant behavior only at partial pressures of oxygen significantly less than 150 torr, the pressure of oxygen in normal air. Such low oxygen partial pressures are found in most tissues under physiological conditions. At higher oxygen pressures, β-carotene loses its antioxidant activity and shows an autocatalytic, prooxidant effect, particularly at relatively high concentrations. Similar oxygen-pressure-dependent behavior may be shown by other compounds containing many conjugated double bonds.