Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China.
Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing 210095, China.
Sci Total Environ. 2022 Aug 25;836:155632. doi: 10.1016/j.scitotenv.2022.155632. Epub 2022 May 4.
Oxathiapiprolin is an efficient and chiral fungicide for peronosporomycetes. The enantioselective environmental behavior and ecotoxicity of oxathiapiprolin are still unclear. The enantioselectivity of oxathiapiprolin enantiomers was explored, including their acute toxicity toward aquatic plants (Auxenochlorella pyrenoidosa and Soirodela polyrhiza) along with their influence on photosynthetic pigment production, the acute toxicity and morphological differences for the embryos, larvae and adult stages of zebrafish (Danio rerio), and the degradation in four typical soils (aerobic, anaerobic and sterilized conditions). The enantioselective toxicity of oxathiapiprolin showed that the toxicity of R-oxathiapiprolin was 1.8-2.1 times higher than that of S-oxathiapiprolin toward the two aquatic plants. In particular, the content of photosynthetic pigments decreased significantly stronger after exposure to R-oxathiapiprolin compared with S-oxathiapiprolin. The LC values of R-oxathiapiprolin in zebrafish in the different life stages were 1.6-2.1 times higher than those of S-oxathiapiprolin. The zebrafish embryos were most sensitive to the oxathiapiprolin enantiomers. After exposure to R-oxathiapiprolin, zebrafish embryos showed noticeable hatching delays, inhibition or deformation. R-oxathiapiprolin degraded preferentially in all four soils, with an enantiomeric fraction (EF) ranging from 0.28 to 0.42 under aerobic conditions. Enantioselective degradation was not found under anaerobic and sterilized conditions. The enantioselectivity of new chiral pesticides should be fully considered in risk assessments to provide a basis for the development and preparation of pure optical enantiomers.
唑吡普林是防治卵菌纲病害的高效手性杀菌剂。唑吡普林对映体的环境行为和生态毒性仍不清楚。本研究探索了唑吡普林对映体的对映选择性，包括其对水生植物（蛋白核小球藻和斜生栅藻）的急性毒性，以及对光合色素产生的影响，对斑马鱼（胚胎、幼虫和成年期）的急性毒性和形态差异，以及在四种典型土壤（有氧、厌氧和灭菌条件）中的降解情况。唑吡普林对映体的毒性选择性表明，R-唑吡普林对两种水生植物的毒性比 S-唑吡普林高 1.8-2.1 倍。特别是，与 S-唑吡普林相比，暴露于 R-唑吡普林后，光合色素的含量明显下降得更厉害。R-唑吡普林在不同生命阶段的斑马鱼的 LC 值比 S-唑吡普林高 1.6-2.1 倍。唑吡普林对映体对斑马鱼胚胎最敏感。暴露于 R-唑吡普林后，斑马鱼胚胎孵化延迟、抑制或变形明显。R-唑吡普林在所有四种土壤中优先降解，有氧条件下对映体分数（EF）范围为 0.28-0.42。在厌氧和灭菌条件下未发现对映体选择性降解。在风险评估中应充分考虑新手性农药的对映体选择性，为纯光学对映体的开发和制备提供依据。
