A Singlet Oxygen Priming Mechanism: Disentangling of Photooxidative and Downstream Dark Effects
A Singlet Oxygen Priming Mechanism: Disentangling of Photooxidative and Downstream Dark Effects
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单线态氧引发机制：解开光氧化和下游暗效应
DOI：
10.1021/acs.joc.0c01712
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Greer, Alexander
中科院分区：
文献类型：
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作者：
Jabeen, Shakeela;Farag, Maria;Malek, Belaid;Choudhury, Rajib;Greer, Alexander
由三线态双氧光敏化获得的空气中的单线态氧与烯烃表面活性剂（8-甲基壬-7-烯-1磺酸盐）反应，产生“烯”氢过氧化物，在黑暗中使浮游大肠杆菌（E. coli）失活。 “烯”氢过氧化物光产物本身没有毒性，但在用单线态氧预处理细菌后它们变得有毒。在空气/液体界面测得烯烃表面活性剂单线态氧的总猝灭速率常数(kT)为1.1×106M–1s–1。通过一种称为单线态氧引发 (SOP) 的新机制，单线态氧会产生氢过氧化物，然后产生过氧自由基、四氧化物和分解产物，它们也能促进消毒，因此提供“一二”的效果。这会在难以察觉的暗反应中产生强烈的二次毒性作用。这些结果提供了对暴露于单线态氧后具有暗毒性效应的外源烯烃辅助杀伤的深入了解。
Airborne singlet oxygen obtained from photosensitization of triplet dioxygen is shown to react with an alkene surfactant (8-methylnon-7-ene-1 sulfonate) leading to “ene” hydroperoxides that in the dark inactivate planktonicEscherichia coli (E. coli). The “ene” hydroperoxide photoproducts are not toxic on their own, but they become toxic after the bacteria are pretreated with singlet oxygen. The total quenching rate constant (kT) of singlet oxygen of the alkene surfactant was measured to be 1.1 × 106M–1s–1at the air/liquid interface. Through a new mechanism called singlet oxygen priming (SOP), the singlet oxygen leads to hydroperoxides then to peroxyl radicals, tetraoxides, and decomposition products, which also promote disinfection, and therefore offer a “one-two” punch. This offers a strong secondary toxic effect in an otherwise indiscernible dark reaction. The results provide an insight into assisted killing by an exogenous alkene with dark toxicity effects following exposure to singlet oxygen.