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[学术文献 ] The stereoselective bioactivity and mechanism of indoxacarb against Spodoptera frugiperda 进入全文
Pest Management Science 期刊
BACKGROUND：Indoxacarb, a type of chiral pesticide, is used to control Lepidoptera insects. Most studies had focused on the environmental behavior and selective toxicity of indoxacarb enantiomers, and the mechanism behind its selective biological activity against target organisms is not well understood. RESULTS：Spodoptera frugiperda was selected as the target insect. The lethal concentrations (96 h) of indoxacarb enantiomers on S. frugiperda were 2.61 mg/kg (S-indoxacarb) and 463.52 mg/kg (R-indoxacarb). S-Indoxacarb resulted in stronger oxidative damage to S. frugiperda than R-indoxacarb, and catalase and malondialdehyde were upregulated by 40.46% and 68.64% respectively after treatment with S-indoxacarb. Furthermore, cytochrome P450 and carboxylesterase were activated by S-indoxacarb, increasing by 39.62% and 63.68% respectively. Decarbomethoxyllated JW062 (DCJW), a metabolite of indoxacarb, has insecticidal activity. The concentration of DCJW in the S-indoxacarb treatment group was 2.73 times that in the R-indoxacarb treatment group. Molecular docking results demonstrated that S-indoxacarb could spontaneously bind to metabolic enzymes and be metabolized. CONCLUSIONS：Enantiomeric bioactivity of indoxacarb enantiomers against on S. frugiperda was observed. S-Indoxacarb demonstrated remarkable insecticidal efficacy. Upon ingestion by S. frugiperda, it induced oxidative damage. Furthermore, S-indoxacarb was metabolized to DCJW, which has a significant role in its insecticidal properties. The selective bioactivity of indoxacarb enantiomers in S. frugiperda might be attributed to the enantiomeric metabolites. These findings offer a new perspective on the selective mechanisms of chiral pesticides. © 2025 Society of Chemical Industry.
[学术文献 ] Combination of biotransformation and metabolomics reveals tolfenpyrad-induced hepatocytotoxicity 进入全文
Science of The Total Environment 期刊
Tolfenpyrad (TFP) is an extensively used pesticide that inevitably leads to human exposure to both TFP and its transformation product residues. However, the biotransformation of TFP in humans has not been elucidated, and the toxicity of TFP along with its biotransformation products remains largely unknown. In this study, the biotransformation process of TFP was investigated using human liver microsomes and human hepatic cells. Endogenous metabolic changes in the cells were studied to investigate the hepatocytotoxicity of TFP at environmentally relevant concentrations. Fourteen phase I biotransformation products and four phase II TFP products were characterized, among which twelve products were identified for the first time. The oxidative product tolfenpyrad-benzoic acid (PT-CA) was particularly abundant and stable. Further hepatotoxicity assessments and metabolic studies demonstrated comparable metabolic profiles for TFP and PT-CA in HepG2 cells, with both significantly disrupting purine and glutathione metabolism. These processes are closely associated with oxidative stress, mitochondrial damage, and cell death. Our results provide novel perspectives on the biotransformation, metabolism, and hepatotoxicity of TFP, thereby highlighting the non-negligible toxicity of its crucial biotransformation product PT-CA in environmental risk assessments.
[学术文献 ] Habitual coffee and tea consumption and risk of cataract: A prospective cohort study from the UK Biobank 进入全文
Clinical Nutrition ESPEN 期刊
Background：To study the association of habitual coffee and tea consumption with the risk of cataract. Methods：This prospective cohort study enrolled UK Biobank participants between 2006 and 2010, and prospectively followed them up for cataract diagnosis. We examined the associations of self-reported intake of tea and coffee and the calculated combined caffeine intake, with the risk of incident cataract. Cox proportional hazards models were analyzed after adjusting for age, sex, race, diabetes, Townsend Index, income, education, smoking and alcohol status. Results：A total of 444,787 UK Biobank participants aged from 37 to 73 years old who had no cataract at baseline were included. Coffee intake of 2–3 cups/day (HR 0.973, 95% CI 0.949–0.998) or tea intake of 4–6 cups/day (HR 0.962, 95% CI 0.934–0.990) or combination caffeine intake of 160.0–235.0 mg/day (HR 0.950, 95% CI 0.925–0.976) were linked with the lowest risk of incident cataract. Cox models with restricted cubic splines showed J-shaped associations of coffee, tea, and combined caffeine intake with the risk of cataract (all p for nonlinear <0.001). Conclusions：Moderate habitual consumption of coffee and tea is associated with a lower risk of cataract. To maximize the protective effect against cataract, it is advisable to control total caffeine intake from coffee and tea within a range of 160.0–235.0 mg/day.
[相关专利 ] 一种基于茶叶预处理的茶叶农药残留检测系统及方法 进入全文
中国专利
本发明涉及农药检测技术领域，具体公开了一种基于茶叶预处理的茶叶农药残留检测系统及方法，数据采集模块，用于采集预处理茶叶中影响农药检测准确度的干扰物含量数据；通过结合茶叶中的干扰物含量数据，可以对不同批次的茶叶农药残留检测准度影响系数进行计算，该数据可以反映当前批次茶叶中的干扰物对农药检测结果的影响程度的高低，从而决策是否进行农药残留检测作业，之后通过结合该数据，可以对实际检测到的数据进行修正计算，从而获得处理后的不同批次茶叶的农药残留值，该数据在经过修正后会更加接近真实值，可以真实地反映农药残留的情况以及含量，从而提高茶叶农药残留检测结果的准确性。
[学术文献 ] Influence of heteroatom doping in tuning fluorescence of carbon dots for detection of pendimethalin and indoxacarb with different mechanisms 进入全文
Emergent Materials 期刊
In this study, Sapindus mukorossi (soapnut, abbreviated as “SN”) fruits were used as a green precursor to synthesize carbon dots (CDs) through hydrothermal (named as SNCDs-HT) and acid carbonization (named as SNCDs-AC) methods, with a focus on comparing their optical properties and fluorescence response to pesticide detection. SNCDs-HT exhibited blue fluorescence with emission/excitation wavelengths (λEm/Ex) at 418/334 nm, while SNCDs-AC displayed green fluorescence with λEm/Ex at 525/424 nm. Various characterization techniques were employed to analyze the optical properties and surface functionalities of both CDs. The emission intensity of SNCDs-HT decreased proportionally with increasing concentrations of pendimethalin (PNM) ranging from 1 to 140 μM. In contrast, SNCDs-AC responded to indoxacarb (INC) concentrations in the range of 0.05 to 100 μM through a fluorescence quenching mechanism. The incorporation of heteroatoms (phosphorus) in SNCDs-AC not only altered their optical properties but also enhanced their sensing capabilities compared to SNCDs-HT. Notably, the quantum yield (QY) of SNCDs-HT was calculated to be 12.2%, whereas SNCDs-AC demonstrated a higher QY of 21.7%, underscoring the effectiveness of heteroatom doping in improving fluorescence efficiency. This study presents a novel approach to tailor the optical properties and sensing performance of CDs through heteroatom doping, offering significant potential for environmental monitoring applications.
[会议论文 ] Pyrethroid analysis in fresh tea leaves: preliminary study in building the low volume extraction 进入全文
IOP Conference Series-Earth and Environmental Science
Low volume extraction using rotary agitator was used in order to develop method analysis for simultaneous determination of five pyrethroids (lambda-cyhalothrin, permethrin, cypermethrin, fenvalerate, and deltamethrin) in fresh tea leaves. The application of n-hexane, n-hexane with some modifications, acetonitrile, and ethyl acetate were tested to extract the pyrethroids before being injected to gas chromatography coupled with electron capture detector. The experiment was conducted in spike-experiment where known amount of pyrethroids were fortified into the fresh tea leaves and the results were compared to the no-spike-experiment where no pyrethroids were added. Result showed that n-hexane was able to extract all target pyrethroids from fresh tea leaves but the recovery values were low. Meanwhile, acetonitrile and ethyl acetate were able to extract pyrethroids with higher recovery values compare to n-hexane but only acetonitrile gave recovery values that were in the range suggested by European Union. Therefore acetonitrile is suggested as a solvent for low volume extraction of pyrethroids from fresh tea leaves.
