School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
J Agric Food Chem. 2024 Aug 28;72(34):18880-18889. doi: 10.1021/acs.jafc.4c05227. Epub 2024 Aug 20.
The degradation of isopyrazam in soils was investigated through kinetics, microbial contributions, and transformation products (TPs). Then the acute toxicity of isopyrazam and its TP to was explored. The half-lives of isopyrazam in cinnamon soil, red soil, and black soil were 82.2, 141.7, and 120.3 days, respectively. A strain ( sp. A01) isolated from cinnamon soil could degrade 72.9% of isopyrazam at 10 mg/L after 6 days in a Luria-Bertani medium. Six TPs were observed with sp. A01, and three of them were found in soil as well. Through the inhibition of cytochrome P450 enzymes, the production of oxidized isopyrazam was blocked. Microbial mediated hydroxylation, epoxidation, and dehydration were the main degradation pathways of isopyrazam. The acute toxicity results showed that the EC of 3-(difluoromethyl)--(9-(2-hydroxypropan-2-yl)-1,2,3,4-tetrahydro-1,4-methanonaphthalen-6-yl)-1-methyl-1-pyrazole-4-carboxamide to was 40 times higher than that of the parent. This work provides new insights for understanding the degradation behavior of isopyrazam in soil.
采用动力学、微生物贡献和转化产物（TPs）研究了异恶唑草酮在土壤中的降解情况。然后，研究了异恶唑草酮及其 TP 对 的急性毒性。异恶唑草酮在肉桂土、红土和黑土中的半衰期分别为 82.2、141.7 和 120.3 天。从肉桂土中分离到的一株菌（ sp. A01）在 Luria-Bertani 培养基中 10mg/L 下 6 天可降解 72.9%的异恶唑草酮。 sp. A01 观察到 6 种 TP，其中 3 种也在土壤中发现。通过抑制细胞色素 P450 酶，阻止了氧化异恶唑草酮的产生。微生物介导的羟化、环氧化和脱水是异恶唑草酮的主要降解途径。急性毒性结果表明，3-(二氟甲基)-1-甲基-1-吡唑-4-甲酰胺-9-(2-羟基丙-2-基)-1,2,3,4-四氢-1,4-甲萘-6-基）对 的 EC 比母体高 40 倍。这项工作为了解异恶唑草酮在土壤中的降解行为提供了新的见解。
