Abstract

Racemates in the environment can lead to inaccurate risk assessment. To obtain the enantiomeric level information of benzovindiflupyr for accurate risk assessment, the absolute configuration of benzovindiflupyr was first confirmed, and the enantioseparation method was developed by supercritical fluid chromatography tandem mass spectrometry. The enantioselectivity for bioactivity and toxicity was investigated, and the mechanism was explored by molecular docking and detecting succinate dehydrogenase (SDH) activity and content of succinate acid.  1S , 4R -(−)-benzovindiflupyr was identified as the most active against the six targeted phytopathogens, which showed higher 1.7–54.5 times than  1R , 4S -(+)-benzovindiflupyr. Additionally,  1S , 4R -(−)-benzovindiflupyr (LD50: 21.54 μg L⁻¹) was 103.7 times more toxic than  1R , 4S -(+)-benzovindiflupyr against  Daphnia magna .  1S , 4R -(−)-benzovindiflupyr had a stronger affinity for SDH and significantly inhibited SDH activity, resulting in an increase in succinate acid in the tricarboxylic acid cycle, while its downstream products, fumaric and  L -malic acid were significantly reduced. Moreover, the dissipation behavior of benzovindiflupyr on three vegetables was evaluated.  1S , 4R -(−)-benzovindiflupyr was preferentially degraded in tomato, but opposite in leaves. The enantioselectivity in pepper and cucumber leaves was the same as in tomato, while there was no enantioselectivity in pepper and cucumber. The study provides a basis for accurate risk assessment and the development of high-effective and low-risk fungicides.

Science of The Total Environment, IF="10.073

https://doi.org/10.1016/j.scitotenv.2022.160535