Alternative brominated flame retardants (BFRs) have become prevalent as a consequence of restrictions on the use of polybrominated diphenyl ethers (PBDEs). For risk assessment of these alternatives, knowledge of their metabolism via cytochrome P450 enzymes is needed. We have previously proved that density functional theory (DFT) is able to predict the metabolism of PBDEs by revealing the molecular mechanisms. In the current study, the reactivity of 1,2-bis(2,4,6-tribromophenoxy)ethane and structurally similar chemicals with the Compound I model representing the active site of P450 enzymes was investigated. The DFT calculations delineated reaction pathways which lead to reasonable explanations for products that were detected by wet experiments, meanwhile intermediates which cannot be determined were also proposed. Results showed that alkyl hydrogen abstraction will lead to bis(2,4,6-tribromophenoxy)ethanol, which may undergo hydrolysis yielding 2,4,6-tribromophenol, a neurotoxic compound. In addition, a general pattern of oxidation reactivity regarding the 2,4,6-tribromophenyl moiety was observed among several model compounds. Our study has provided insights for convenient evaluation of the metabolism of other structurally similar BFRs.

中文翻译：

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通过细胞色素P450s的化合物I模型对1,2-双（2,4,6-三溴苯氧基）乙烷（BTBPE）的氧化反应性。

由于限制了多溴联苯醚（PBDEs）的使用，替代溴化阻燃剂（BFR）已变得普遍。为了评估这些替代品的风险，需要了解其通过细胞色素P450酶代谢的知识。我们先前已经证明，密度泛函理论（DFT）能够通过揭示分子机制来预测PBDEs的代谢。在当前的研究中，研究了1,2-双（2,4,6-三溴苯氧基）乙烷和结构相似的化学物质与代表P450酶活性位点的化合物I模型的反应性。DFT计算描绘了反应途径，从而为通过湿法实验检测到的产物提供了合理的解释，同时还提出了无法确定的中间体。结果表明，烷基氢的提取将导致双（2,4,6-三溴苯氧基）乙醇发生水解，生成神经毒性化合物2,4,6-三溴苯酚。另外，在几种模型化合物中观察到关于2,4,6-三溴苯基部分的氧化反应性的一般模式。我们的研究为方便评估其他结构相似的BFR的代谢提供了见识。