Free-radical chemistry of cigarette smoke and its toxicological implications.
Free-radical chemistry of cigarette smoke and its toxicological implications.
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DOI：
10.1289/ehp.8564111
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发表时间：
1985-12
影响因子：
10.4
通讯作者：
Pryor WA
中科院分区：
文献类型：
--
作者：
Church DF;Pryor WA
香烟烟雾中含有两种截然不同的自由基，一种在焦油中，一种在气相中。焦油相含有几种相对稳定的自由基；我们已经确定主自由基为醌/对苯二酚（Q/QH2）络合物持有在焦油基质。我们认为这种Q/QH2聚合物是一种活性氧化还原系统，能够还原分子氧产生超氧化物，最终导致过氧化氢和羟基自由基。此外，我们已经证明焦油中的主自由基在体外可能通过共价结合与DNA发生反应。香烟烟雾的气相中含有少量的以氧和碳为中心的自由基，它们比焦油相的自由基活性强得多。这些气相自由基不是在火焰中产生的，而是由NO氧化成NO2在稳定状态下产生的，然后与烟雾中的活性物质如异戊二烯发生反应。我们认为这些自由基和这些自由基反应产生的亚稳态产物可能是导致α - 1蛋白酶抑制剂被新鲜烟雾失活的原因。香烟烟雾将硫醇氧化为二硫化物；我们认为活性氧化剂是NO和NO2。烟对脂质过氧化的影响是复杂的，并对此进行了讨论。我们还讨论了烟雾中的自由基在一些自由基介导的疾病过程中的毒理学意义，包括肺气肿和癌症。
Cigarette smoke contains two very different populations of free radicals, one in the tar and one in the gas phase. The tar phase contains several relatively stable free radicals; we have identified the principal radical as a quinone/hydroquinone (Q/QH2) complex held in the tarry matrix. We suggest that this Q/QH2 polymer is an active redox system that is capable of reducing molecular oxygen to produce superoxide, eventually leading to hydrogen peroxide and hydroxyl radicals. In addition, we have shown that the principal radical in tar reacts with DNA in vitro, possibly by covalent binding. The gas phase of cigarette smoke contains small oxygen- and carbon-centered radicals that are much more reactive than are the tar-phase radicals. These gas-phase radicals do not arise in the flame, but rather are produced in a steady state by the oxidation of NO to NO2, which then reacts with reactive species in smoke such as isoprene. We suggest that these radicals and the metastable products derived from these radical reactions may be responsible for the inactivation of alpha 1-proteinase inhibitor by fresh smoke. Cigarette smoke oxidizes thiols to disulfides; we suggest the active oxidants are NO and NO2. The effects of smoke on lipid peroxidation are complex, and this is discussed. We also discuss the toxicological implications for the radicals in smoke in terms of a number of radical-mediated disease processes, including emphysema and cancer.