Pydiflumetofen (PYD) is primarily used to control fungal disease. The potential risks posed by PYD enantiomers to the aquatic ecosystem are currently unclear. In this study, the enantioselective toxicity and fate of PYD in Danio rerio were investigated, and the enantioselective toxic mechanism and metabolic pathway were explored. The acute toxicity of R-PYD was 10.7–14.7-fold than that of S-PYD against Danio rerio embryos, larvae, and adults. Meanwhile, R-PYD presented a stronger effect on embryo hatching and abnormalities, adult tissue damage and oxidative stress. R-PYD inhibited the succinate dehydrogenase (SDH) activity more than S-PYD because of its better interaction with SDH with a lower binding free energy (-59.35 kcal/mol), explaining the mechanism of enantioselective toxicity. Remarkable enantioselectivity was observed in uptake, distribution, and elimination. R-PYD showed preferential uptake with the higher uptake rate constants and slow metabolism with a longer half-life, resulting in the bioaccumulation of R-PYD with higher BCF_k (7.37 at 0.05 mg/L and 14.69 at 0.2 mg/L). Besides, muscle is an important tissue for PYD accumulation, existing potential food risk. Eleven PYD metabolites were qualitatively identified, and the metabolic pathway was proposed, including hydroxylation, N-demethylation, demethoxylation, hydrolysation (phase Ⅰ), and acetylation and glucuronidation (phase Ⅱ). The predicted toxicity of the metabolite indicated that several highly toxic metabolites need to be considered in the future. This study provides a new perspective for evaluating the ecological and human health risks of chiral pesticides.

吡氟美托芬 (PYD) 主要用于控制真菌病害。PYD 对映异构体对水生生态系统造成的潜在风险目前尚不清楚。本研究探讨了斑鱼中PYD的对映选择性毒性和归宿，探讨了对映选择性毒性机制和代谢途径。R - PYD对斑马鱼胚胎、幼虫和成虫的急性毒性是S -PYD的10.7-14.7倍。同时，R -PYD对胚胎孵化和异常、成体组织损伤和氧化应激的影响更强。R -PYD 比S更能抑制琥珀酸脱氢酶 (SDH) 活性-PYD，因为它与 SDH 更好的相互作用，具有较低的结合自由能 (-59.35 kcal/mol)，解释了对映选择性毒性的机制。在吸收、分布和消除中观察到显着的对映选择性。R -PYD 表现出优先吸收，具有较高的吸收速率常数和较慢的代谢，具有较长的半衰期，导致R -PYD 的生物累积具有较高的 BCF _k（0.05 mg/L 时为 7.37，0.2 mg/L 时为 14.69）。此外，肌肉是PYD积累的重要组织，存在潜在的食物风险。定性鉴定了 11 种 PYD 代谢物，提出了代谢途径，包括羟基化、N-去甲基化、去甲氧基化、水解（Ⅰ期）、乙酰化和葡萄糖醛酸化（Ⅱ期）。代谢物的预测毒性表明，未来需要考虑几种剧毒代谢物。该研究为评估手性农药的生态和人类健康风险提供了新的视角。