Comprehensive Assessment of Enantioselective Bioactivity, Toxicity, and Dissipation in Soil of the Chiral Herbicide Flurtamone
Yanqing Zhang, Liangliang Zhou, Rui Li, Yanhong Li, Yuting Tan, Haiyan Shi, Minghua Wang
Abstract
Flurtamone is a typical chiral pesticide with a pair of enantiomers. In this study, the enantioselective biological effects of flurtamone enantiomers were systematically investigated. The bioactivities of R -flurtamone were 6.3–35.6 and 1.7–9.9 times higher than S - and R ac-flurtamone, respectively. The contribution of the R -enantiomer to herbicidal activity was 86.3–97.3%. The carotenoid content in the R -flurtamone treatment group was 1.31–2.14 times lower than that in the S -flurtamone treatment group. Molecular docking found that flurtamone can form aromatic H-bonds with phenylalanine (PHE) 233 of phytoene desaturase (PDS), while R -flurtamone can form π–π stacking with PHE 202 and PHE 311. The binding energies of R - and S -flurtamone were −10.239 and −7.555 kcal/mol, respectively. Furthermore, the acute toxicity levels to Selenastrum capricornutum of R - and R ac-flurtamone were both highly toxic, and S -flurtamone has moderate toxicity. S -Flurtamone dissipated preferentially. Therefore, the development of R -flurtamone can decrease environmental risks and protect human health.