Institute of Molecule and Crystal Physics, Ufa Research Centre, Russian Academy of Sciences, Ufa, Russia.
Phys Chem Chem Phys. 2013 Jun 21;15(23):9125-35. doi: 10.1039/c3cp50614b. Epub 2013 May 3.
Resonance attachment of low-energy electrons to xenobiotic molecules, 2,4-dichlorophenoxyacetic acid (2,4-D), dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE), was investigated under gas-phase conditions by means of complementary experimental techniques. Electron transmission spectroscopy (ETS) and dissociative electron attachment spectroscopy (DEAS), in the 0-6 eV and 0-15 eV energy range, respectively, were applied with the aim of modeling the behavior of these pesticide molecules under reductive conditions in vivo. Formation of long-lived parent molecular anions and fragment negative ions was observed at incident electron energies very close to zero, in agreement with the results of density functional theory calculations. The gas-phase DEA process, analogous to dissociative electron transfer in solution, was considered as a model for the initial step which occurs in the intermembrane space of mitochondria when a xenobiotic molecule captures an electron "leaked" from the respiratory chain. A possible involvement of the fragments produced by DEA to the pesticides under investigation into cellular processes is discussed. It is concluded that the free radicals and potential DNA adducts formed by DEA are expected to be dangerous for mitochondrial functionalities, while several of the products observed could act as messenger molecules, thus interfering with the normal cellular signaling pathways.
在气相条件下，通过互补的实验技术研究了低能电子与外源性分子、2,4-二氯苯氧乙酸（2,4-D）、滴滴涕（DDT）和滴滴伊（DDE）的共振附着。电子传输光谱（ETS）和电子分解附谱（DEAS）分别在 0-6eV 和 0-15eV 的能量范围内被应用，目的是模拟这些农药分子在体内还原性条件下的行为。在非常接近零的入射电子能量下，观察到长寿命的母体分子阴离子和碎片负离子的形成，这与密度泛函理论计算的结果一致。气相 DEA 过程类似于溶液中的电子转移，被认为是异生物质分子在捕获从呼吸链“泄漏”的电子时，在线粒体的跨膜间隙中发生的初始步骤的模型。讨论了 DEA 产生的碎片可能参与到所研究的杀虫剂中的情况。结论是，DEA 形成的自由基和潜在的 DNA 加合物预计对线粒体功能是危险的，而观察到的几种产物可能作为信使分子起作用，从而干扰正常的细胞信号通路。
