In this study, abiotic transformation of an important strobilurin fungicide, kresoxim-methyl, was investigated under controlled laboratory conditions for the first time by studying its kinetics of hydrolysis and photolysis, degradation pathways and toxicity of possibly formed transformation products (TPs). The results indicated that kresoxim-methyl showed a fast degradation in pH9 solutions with DT₅₀ of 0.5 d but relatively stable under neutral or acidic environments in the dark. It was prone to photochemical reactions under simulated sunlight, and the photolysis behavior was easily affected by different natural substances such as humic acid (HA), Fe³⁺and NO₃⁻which are ubiquitous in natural water, showing the complexity of degradation mechanisms and pathways of this chemical compound. The potential multiple photo-transformation pathways via photoisomerization, hydrolyzation of methyl ester, hydroxylation, cleavage of oxime ether and cleavage of benzyl ether were observed. 18 TPs generated from these transformations were structurally elucidated based on an integrated workflow combining suspect and nontarget screening by high resolution mass spectrum (HRMS), and two of them were confirmed with reference standards. Most of TPs, as far as we know, have never been described before. The in-silico toxicity assessment showed that some of TPs were still toxic or very toxic to aquatic organisms, although they exhibit lower aquatic toxicity compared to the parent compound. Therefore, the potential hazards of the TPs of kresoxim-methyl merits further evaluation.

在这项研究中，通过研究其水解和光解动力学、降解途径和可能形成的转化产物 (TP) 的毒性，首次在受控实验室条件下研究了一种重要的嗜球果伞素杀菌剂醚菌酯的非生物转化。结果表明，醚菌酯在 pH9 溶液中降解迅速，DT ₅₀为 0.5 d，但在黑暗中的中性或酸性环境中相对稳定。在模拟阳光下易发生光化学反应，光解行为易受不同天然物质如腐植酸（HA）、Fe ³⁺和NO ₃ ^{−的影响。}它们在天然水中无处不在，显示了该化合物降解机制和途径的复杂性。观察到通过光异构化、甲酯水解、羟基化、肟醚裂解和苄醚裂解的潜在多重光转化途径。基于通过高分辨率质谱 (HRMS) 结合可疑目标和非目标筛选的集成工作流程，从这些转化中产生的 18 个 TP 在结构上得到了阐明，其中两个通过参考标准进行了确认。据我们所知，大多数 TP 以前从未被描述过。计算机内毒性评估表明，一些 TP 对水生生物仍然有毒或毒性很大，尽管与母体化合物相比，它们表现出较低的水生毒性。因此，醚菌酯类药物的潜在危害值得进一步评估。