氟虫腈对斑马鱼和小菜蛾毒性的手性选择性研究

手性农药分子的不同对映体在环境中的降解速率和对于生物的毒性可能存在很大的差异,因此拆分并使用对靶标生物毒性较高或对非靶标生物毒性较低的单一或浓缩的对映体配方可以有效地降低杀虫剂的环境风险.本文用手性柱拆分了一种广泛使用的手性农药,氟虫腈的两种对映体,研究了这两种对映体和消旋体对靶标生物小菜蛾和非靶标生物斑马鱼的急性毒性.结果表明氟虫腈对受试靶标和非靶标生物的毒性均无手性选择性,说明无法通过对氟虫腈进行手性拆分并使用单一对映体配方来降低氟虫腈的环境风险.这一结论间接支持了农业部新近出台的禁止氟虫腈用于防治农田害虫的政策.

Acute toxicities of fipronil enantiomers to zebrafish and diamondback moth

The two enantiomers of a chiral pesticide may differ in their degradation kinetics in environment and toxicities toward certain species. The enantiomer-specific effects indicate that it would be environmentally friendly to use pesticide formulations with single- or enriched enantiomers that are either more active toward target insects or less toxic to non-target species. In this work, the two enantiomers of a chiral pesticide, fipronil, were separated and their toxicities to a target species, diamondback moth, and a non-target species, zebra fish were examined. It was found that fipronil showed no enantioselective toxicity to both the target and non-target species. As such, using single or enriched fipronil enantiomer formulation is unlikely an effective approach to reduce risks of fipronil to non-target species. This conclusion indirectly supports the new policy of the Ministry of Agriculture of China to ban the agricultural use of fipronil.