手性农药茚虫威对映体在茶叶生长加工过程中降解差异机制

“十二五”以来，茚虫威逐渐成为防治茶园叶蝉等害虫、用于替代高毒、高水溶性农药的首选。据文献报道，茚虫威手性对映体中，S-体杀虫活性高且毒性比R-体小，而代谢物DCJW的毒性则大于茚虫威本身。在前面的青年基金研究中，我们发现了茚虫威在茶叶生长加工中存在对映体降解速率差异，S-体降解快于R-体,这样就会导致药效下降且残留毒害风险增大，对其中的选择性降解机制也不清楚。因此，本项目选择以茶叶为载体，利用代谢轮廓分析法和组学策略，借助UPCC/UPLC/APGC-QTOF-MS筛查技术，研究茚虫威对映体在茶叶生长-加工-冲泡中的代谢产物及迁移转化差异的规律、不同酶对对映体代谢的影响，从而找到关键控制点、明确关键代谢酶，从生化水平解析明确茚虫威对映体降解差异的机制。本项目为促进手性农药在茶园合理施用、保障茶叶饮用安全提供科学依据，有助于后续茶园农药减施增效、降低茶叶中农药残留，提高茶叶质量安全水平。

In recent years, indoxacarb becomes the first choice for controlling leaf hoppers and other pests in the tea garden to replace other high toxic and high water-soluble insecticides. It has been reported that the S-enantiomer of indoxacarb has higher insecticidal activity and less toxicity than R-enantiomer, and the toxicity of metabolite DCJW was much higher than that of indoxacarb its own. During the study of our previous National Natural Science Foundation of China Youth Fund, we have found that the chiral pesticide-indoxacarb enantiomers selectively degraded in the growth and processing of tea. The S-enantiomer degraded faster than the R-enantiomer, that will lead to decreased efficacy and increased risk of residual toxicity, and the selective degradation mechanism is unclear.. Therefore, we propose to use metabolic profiling and omics strategies, with the help of UPCC/UPLC/APGC-QTOF-MS screening technology to study the differences of metabolites, migration and transformation for indoxacarb enantiomers in the growth, processing and brewing of tea, and the effects of different enzymes on the metabolism of indoxacarb enantiomers, so as to clarify the key metabolic enzymes, the key points and the mechanism of selective degradation differences for enantiomers at biochemical level..The project will provide scientific basis data for the promotion of chiral pesticides reasonable application in tea garden, and ensure the safety of tea drinking. It is also helpful for further reducing the application of chiral pesticide and improving the efficiency, reducing pesticide residue amounts in tea and improving the quality and safety of tea.