State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, China.
Pest Manag Sci. 2023 Jul;79(7):2353-2364. doi: 10.1002/ps.7412. Epub 2023 Mar 8.
Indoxacarb is a chiral insecticide with excellent insecticidal activity against lepidopterous insects. Because of their enantioselectivity, chiral pesticides' environmental behavior at the enantiomeric level has been highlighted. The chiral stability, enantioselective bioaccumulation, biotransformation behavior of indoxacarb to a non-target insect silkworm are still unclear.
A chiral analysis method for indoxacarb and its metabolite DCJW in silkworm was developed using liquid chromatography and high-resolution mass spectrometry (HPLC/HRMS). In silkworms, the recoveries of indoxacarb and DCJW were 86.06%-104.52% with relative standard deviation (RSD) < 9.01%. The 96-h lethal concentration (LC ) values of R-indoxacarb, S-indoxacarb, and enriched S-indoxacarb (2.333 S/1R) were 1.08 × 10 , 1.92, and 6.89 mg a.i. L , respectively, according to the acute toxicity test results. When silkworm larvae were exposed to 1/50 of the LC concentration, the bioconcentration factor (BCF) of R-indoxacarb was 0.0296-0.318, and the BCF of S-indoxacarb was 0.0125-0.211. In silkworm larvae, the amount of R-DCJW produced by R-indoxacarb was 0.00610 to 2.34 times that of the parent R-indoxacarb, and the amount of S-DCJW produced by S-indoxacarb was 0.125-36.9 times that of the parent S-indoxacarb.
There was no chiral transition from S-indoxacarb to R-indoxacarb or a transformation from R-indoxacarb to S-indoxacarb. Indoxacarb was preferentially bioaccumulated in silkworm larva, while S-indoxacarb bioconversion into the metabolite S-DCJW was much greater than R-indoxacarb bioconversion into R-DCJW. This study could improve understanding of the indoxacarb accumulation and transformation process in insects, as well as provide more scientific data for indoxacarb environmental and ecological risk assessment. © 2023 Society of Chemical Industry.
茚虫威是一种手性杀虫剂，对鳞翅目昆虫具有优异的杀虫活性。由于其对映体选择性，手性农药在对映体水平上的环境行为受到了关注。茚虫威对非靶标昆虫家蚕的手性稳定性、对映体选择性生物累积、生物转化行为仍不清楚。
建立了一种用液相色谱-高分辨质谱（HPLC/HRMS）分析家蚕中茚虫威及其代谢物 DCJW 的手性分析方法。在蚕体内，茚虫威和 DCJW 的回收率为 86.06%-104.52%，相对标准偏差（RSD）<9.01%。根据急性毒性试验结果，R-茚虫威、S-茚虫威和富集 S-茚虫威（2.333 S/1R）的 96 h 致死浓度（LC ）值分别为 1.08×10 -6 、1.92 和 6.89 mg a.i. L -1 。当家蚕幼虫暴露于 LC 浓度的 1/50 时，R-茚虫威的生物浓缩因子（BCF）为 0.0296-0.318，S-茚虫威的 BCF 为 0.0125-0.211。在家蚕幼虫体内，R-茚虫威生成的 R-DCJW 量是其母体 R-茚虫威的 0.00610-2.34 倍，S-茚虫威生成的 S-DCJW 量是其母体 S-茚虫威的 0.125-36.9 倍。
S-茚虫威没有向 R-茚虫威转化，也没有 R-茚虫威向 S-茚虫威转化。茚虫威优先在家蚕幼虫体内累积，而 S-茚虫威向代谢物 S-DCJW 的转化量明显大于 R-茚虫威向 R-DCJW 的转化量。本研究可提高对手性杀虫剂在昆虫体内的累积和转化过程的认识，为茚虫威环境和生态风险评估提供更多的科学数据。 © 2023 化学工业协会。
