Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China.
Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing, Jiangsu 210095, China; Department of Environmental Agricultural Science, Institute of Environmental Studies and Research, Ain Shams University, Cairo 11566, Egypt.
Sci Total Environ. 2019 Jan 15;648:703-710. doi: 10.1016/j.scitotenv.2018.08.182. Epub 2018 Aug 16.
The enantiomeric environmental behaviors, bioactivities and toxicities of isofenphos‑methyl enantiomers were characterized systematically in this study. (R)‑Isofenphos‑methyl was degraded preferentially in Yangtze River water and different types of vegetables with an enantiomeric fraction (EF) of 0.6 to 0.96. However, (R)‑isofenphos‑methyl was amplified in both Nanjing (EF = 0.32) and Nanchang (EF = 0.27) soil. Our investigations found that there no bidirectional chiral inversion occurred in either Yangtze River water or soils. The bioactivity of (S)‑isofenphos‑methyl was higher than that of its (R)‑enantiomer against different insect targets, such as Meloidogyne incognita, Nilaparvata lugens, Plutella xylostella and Macrosiphum pisi (3.7 to 149 times). (S)‑Isofenphos‑methyl showed higher toxicity for the nontarget organism (1.1 to 32 times). However, (R)‑isofenphos‑methyl possesses 4.0 times more potency than the (S)-form for the nontarget soil organism Eisenia foetida. This study generally could provide more scientific guidance for the corresponding risk assessments of pesticides in addition to providing a new theoretical basis for scientifically and rationally using isofenphos‑methyl.
本研究系统地描述了异丙磷甲酯对映体的环境行为、生物活性和毒性。（R）-异丙磷甲酯在长江水中和不同类型的蔬菜中优先降解，对映体分数（EF）为 0.6 至 0.96。然而，（R）-异丙磷甲酯在南京（EF=0.32）和南昌（EF=0.27）土壤中被放大。我们的研究发现，无论是在长江水还是土壤中，都没有发生双向对映体反转。（S）-异丙磷甲酯对不同的昆虫靶标，如Meloidogyne incognita、Nilaparvata lugens、Plutella xylostella 和 Macrosiphum pisi 的生物活性均高于其（R）-对映体，活性比为 3.7 至 149 倍。（S）-异丙磷甲酯对非靶标生物的毒性更高（1.1 至 32 倍）。然而，（R）-异丙磷甲酯对非靶标土壤生物赤子爱胜蚓的毒性比（S）-异丙磷甲酯高 4.0 倍。本研究除了为异丙磷甲酯的科学合理使用提供新的理论依据外，还可为农药的相应风险评估提供更科学的指导。
