Key Laboratory of Agri-food Safety of Anhui Province, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China.
Key Laboratory of Agri-food Safety of Anhui Province, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China.
J Hazard Mater. 2022 Jun 15;432:128650. doi: 10.1016/j.jhazmat.2022.128650. Epub 2022 Mar 9.
Toxification metabolism of the chiral triazole fungicide prothioconazole in the environment has attracted an increasing amount of attention. To better understand the fate of prothioconazole in aquatic ecosystems and develop a treatment strategy, the stereoselective toxicity, degradation and bioconcentration of prothioconazole were investigated in water with algae at the enantiomer level. There was remarkable enantioselectivity against Chlorella pyrenoidosa, and the highly toxic S-prothioconazole was preferentially degraded with enantiomer fraction values ranging from 0.5 to 0.74. Metabolism experiment results showed that the parent compound was quickly eliminated driven by biodegradation and abiotic degradation (hydrolysis, photolysis). Fourteen phase I and two phase II metabolites involved in the reactions of hydroxylation, methylation, dechlorinating, desulfuration, dehydration and conjugation were identified, where prothioconazole-desthio was the major metabolite. The highly toxic metabolite prothioconazole-desthio persisted in water and hardly degraded with or without C. pyrenoidosa. Furthermore, the reaction system including 1 mg of cobalt coated in nitrogen doped carbon nanotubes and 0.156 g of peroxymonosulfate was used to eliminate prothioconazole-desthio. Approximately 96% prothioconazole-desthio was eliminated and transformed to low toxicity metabolites. This work provides a strategy for the risk evaluation of prothioconazole in aquatic ecosystems and proposes a workable plan for the elimination of pesticide residues in water.
手性三唑类杀菌剂丙硫菌唑在环境中的解毒代谢引起了越来越多的关注。为了更好地了解丙硫菌唑在水生生态系统中的命运并开发处理策略，在藻类的对映体水平上研究了丙硫菌唑在水中的立体选择性毒性、降解和生物富集。对蛋白核小球藻具有显著的对映体选择性，高度有毒的 S-丙硫菌唑优先降解，对映体分数值范围为 0.5 至 0.74。代谢实验结果表明，由于生物降解和非生物降解（水解、光解）的驱动，母体化合物迅速消除。鉴定出涉及羟化、甲基化、脱氯、脱硫、脱水和结合反应的 14 种 I 相和 2 种 II 相代谢物，其中丙硫菌唑-脱巯基是主要代谢物。高毒性代谢物丙硫菌唑-脱巯基在水中持续存在，几乎没有降解，无论是否有蛋白核小球藻存在。此外，在包括氮掺杂碳纳米管上的 1 毫克钴和 0.156 克过一硫酸盐的反应系统中，用于消除丙硫菌唑-脱巯基。约 96%的丙硫菌唑-脱巯基被消除并转化为低毒性代谢物。这项工作为评估丙硫菌唑在水生生态系统中的风险提供了策略，并为消除水中农药残留提出了可行的计划。
