title: Chiral fungicide triadimefon and triadimenol: Stereoselective transformation in greenhouse crops and soil, and toxicity to Daphnia magna.
abstract: Various chiral pesticides are used in greenhouses to ensure high crop yields. However, detailed knowledge on the environmental behavior of such chiral contaminants with respect to enantioselectivity in the greenhouse has received little attention so far. Here, the widely used fungicide triadimefon was chosen as a "chiral probe" to investigate its enantioselective degradation and formation of triadimenol in greenhouse tomato, cucumber, and soil under different application modes. In addition, the stereoselectivity of individual isomers of triadimefon and triadimenol in aquatic toxicity were first studied. Significant differences in their acute toxicity to Daphnia magna were observed among the isomers. Under foliage application or soil irrigation application, S-(+)-triadimefon was preferentially degraded, resulting in relative enrichment of the more toxic R-(-)-enantiomer in tomato, cucumber, and soil. Further enantioselective analysis of converted triadimenol showed that the compositions of the four product stereoisomers were different and closely dependent on environmental conditions: the most toxic RS-(+)-triadimenol was the most preferentially produced isomer in tomato under foliage treatment, while the RR-(+)-triadimenol was proved to be the highest amount of metabolite isomer in cucumber and soil under both treatment modes and in tomato under soil treatment.
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193, China.
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193, China.
authors.forename: Fengshou
authors.initials: F
authors.lastname: Dong
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193, China.
authors.forename: Xingang
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193, China.
authors.forename: Yongtao
authors.initials: Y
authors.lastname: Han
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193, China. Electronic address: zhengyongquan@ippcaas.cn.
authors.forename: Yongquan
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D000383:Agriculture / Q000379:methods; D000818:Animals; D018553:Cucumis sativus / Q000378:metabolism*; D003621:Daphnia; D005638:Fruit / Q000378:metabolism*; D005659:Fungicides, Industrial / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D018551:Solanum lycopersicum / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D013237:Stereoisomerism; D023382:Toxicity Tests, Acute; D014230:Triazoles / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity
chemical_list: D005659:Fungicides, Industrial; D012989:Soil Pollutants; D014230:Triazoles; C032910:triadimefon
keywords: Aquatic toxicity; Degradation; Stereoselectivity; Triadimefon; Triadimenol