Stereoselective bioactivity, toxicity and degradation of novel fungicide sedaxane with four enantiomers under rice-wheat rotation mode

作者：Zhou Tong, Yue Chu, Hongwei Wen, Benkun Li, Dong Xu, Mingna Sun, DanDan Meng, Mei Wang, Tongchun Gao, Jinsheng Duan · 发表于：Ecotoxicology and Environmental Safety · 年份：2022 · DOI：10.1016/j.ecoenv.2022.113784 · 被引用次数：15 · 研究领域：Pesticide and Herbicide Environmental Studies、Fungal Plant Pathogen Control、Pesticide Residue Analysis and Safety

Sedaxane was a novel chiral fungicide that contains four enantiomers. Unfortunately, the stereoselective bioactivity, toxicity and degradation of sedaxane have not been clarified. In this study, we identified the absolute configuration of the four sedaxane enantiomers at first time. The stereoselective bioactivity toward three wheat and rice pathogens, stereoselective acute toxicity to aquatic organisms (Selenastrum capricornutum and Daphnia magna), and stereoselective degradation of sedaxane were studied. The 1 S,2S-(+)-sedaxane possessed 5.4-7.3 times greater bioactivity than 1 R,2R-(-)-sedaxane to Rhizoctonia solani and Rhizoctonia cerealis. Contrarily, the 1 R,2S-(+)-sedaxane had 4.2 times greater activity than 1 S,2S-(+)-sedaxane against Fusarium graminearum. The 1 R,2R-(-)-sedaxane had 2.8 times greater toxicity than 1 S,2S-(+)-sedaxane to S. capricornutum. The chiral determination method used ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The recovery of sedaxane stereoisomers ranged from 83.1 % to 98.2 %, with RSDs (Relative standard deviations) of 1.2 %- 8.4 %. The trans-sedaxane existed stereoselective degradation phenomenon in the rice-wheat rotation mode, and 1 S,2S-(+)-sedaxane was preferentially degraded. Our results would provide scientific importance and practical guidance to the safety evaluation of chiral pesticides.