Characterisation of Neonicotinoid and Pymetrozine Resistance in Strains of Bemisia tabaci(Hemiptera:Aleyrodidae)from China

Four strains of the Q biotype and one of the B biotype of the whitefly Bemisia tabaci collected from China were characterised for resistance to four neonicotinoid insecticides and pymetrozine.Q biotype strains showed moderate to strong resistance to imidacloprid,thiamethoxam and acetamiprid,but little or no cross-resistance to dinotefuron.Resistance to neonicotinoids was consistently associated with resistance to pymetrozine,despite the latter having a distinct（though unresolved）mode of action.The single B biotype strain proved largely susceptible to all the insecticides investigated.Resistance in the Q biotype strains was associated with over-expression of a cytochrome P450 monooxygenase gene,CYP6CM1,whose substrate specificity presumably accounts for the observed cross-resistance profiles.

Synthesis, Crystal Structure and Insecticidal Activities of Novel Neonicotinoid Derivatives

Ten new N-oxalyl derivatives of neonicotinoid compound were designed and synthesized. Their structures were confirmed by ^1H NMR spectra, elemental analysis and X-ray diffraction. The preliminary insecticidal activities of the new compounds were evaluated. The results of bioassays indicate that the title Compounds exhibit moderate insecticidal activities. Surprisingly, the insecticidal activity of compound 7b against bean aphids at 200 mg/kg is 100%, which is comoarable to that of the commercialized imidacloprid.

Synthesis and Crystal Structure of the Optical Activity of (Z)-Nitromethylene Neonicotinoid Analogue

A novel （Z）-nitromethylene neonicotinoid analogue （C23H27Cl2N5O4·2H2O） （II） with optical activity has been synthesized, the structure was characterized by elemental analysis, IR and 1H NMR spectra, and the （Z）-configuration was confirmed by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P1 with a = 7.4638（3）, b = 12.6232（5）, c = 15.2990（6）, α = 71.907（1）, β = 89.397（2）, γ = 80.314（1）°, V = 1349.28（9）3, Z = 2, Dc = 1.340 g/cm3, μ = 0.286 mm-1, Mr = 544.43, F（000） = 572, S = 1.056, R = 0.0801 and wR = 0.2366 for 4998 unique reflections with 3012 observed ones （I 〉 2σ（I））. In the crystal, the dihedral angle between the pyridine and 4-Cl-phenyl rings is 58.13°. Intermolecular O-H···O, C-H···O and C-H···Cl hydrogen bonds involving water molecules stabilize the crystal structure.

Pharmacophore model for neonicotinoid insecticides

一个有效预言 pharmacophore 模型( RMS = 0.634 ， Correl = 0.893 ，重量= 1.463 ，配置= 11.940 )被 3D-QSAR 成功地基于一系列 nAChR (烟碱的醋胆素受体)获得收缩筋，由一个结合氢的领受人组成，一个氢契约施主，一恐水病aliphatic 和一个恐水病的芳香的中心。这个 pharmacophore 模型可以为更高活跃的杀虫药剂的指明和开发提供理论基础。

Developmental toxicity assessment of neonicotinoids and organophosphate esters with a human embryonic stem cell-and metabolism-based fast-screening model

In recent years,neonicotinoids(NEOs)and organophosphate esters(OPEs)have been widely used as substitutes for traditional pesticides and brominated fame-retardants,respectively.Previous studies have shown that those compounds can be frequently detected in environmental and human samples,are able to penetrate the placental barrier,and are toxic to animals.Thus,it is reasonable to speculate that NEOs and OPEs may have potential adverse effects in humans,especially during development.We employed a human embryonic stem cell differentiation-and liver S9 fraction metabolism-based fast screening model to assess the potential embryonic toxicity of those two types of chemicals.We show that four NEO and five OPE prototypes targeted mostly ectoderm specification,as neural ectoderm and neural crest genes were down-regulated,and surface ectoderm and placode markers up-regulated.Human liver S9 fraction's treatment could generally reduce the effects of the chemicals,except in a few specific instances,indicating the liver may detoxify NEOs and OPEs.Our findings suggest that NEOs and OPEs interfere with human early embryonic development.

Synthesis,insecticidal activity and stability study of novel nitromethylene neonicotinoids with five-membered aromatic heterocycles

Twenty-four novel neonicotinoid analogues with nitromethylene and five-membered aromatic heterocycles were designed and synthesized.All target molecular structures have been confirmed by analytical and spectral data.Some compounds exhibited notable insecticidal activities against aphid(Aphis medicaginis)and brown planthopper(Nilaparvata lugens).The aqueous stability test confirmed that the stabilities of those compounds were superior to the leading compound,and the photostability was even better than that of imidacloprid.

Insights into Free and Conjugated Forms of Neonicotinoid Insecticides in Human Serum and Their Association with Oxidative Stress

Following exposure,neonicotinoid insecticides(NEOs)can be metabolized by both Phase Ⅰ and Phase Ⅱ reactions catalyzed by human cytochrome P450 enzymes.However,toxicities of parent NEOs and their metabolites are still unclear,and little is known about biotransformation rates and pathways of NEOs in humans.In this study,98 serum samples collected in China were analyzed for free,conjugated and total forms of six parent NEOs(i.e.,acetamiprid(ACE),imidacloprid(IMI),clothianidin(CLO),thiacloprid(THD),thiamethoxam(THM),and dinotefuran(DIN))and four metabolites(i.e.,N-desmethyl-acetamiprid(N-dm-ACE),1-methyl-3-(tetrahydro-3-furylmethyl)(DIN-U),5-hydroxy-imidacloprid(5-OH-IMI),olefin-imidacloprid(Of-IMI)).NEOs and their metabolites were detected in all serum samples,and the total median concentrations of free,conjugated,and total forms of 10 NEOs were 2.04,2.01,and 5.12 ng/mL,respectively.Conjugated forms of NEOs accounted for only half(53%)of the total forms of NEOs.Based on the profiles of Phase Ⅰ and Phase Ⅱ metabolites of NEOs in serum,it was found that age is a determinant in Phase Ⅰmetabolism of DIN and Phase Ⅱ metabolism of IMI.The Phase Ⅱmetabolites of NEOs are associated with oxidative DNA damage,and the conjugated forms of IMI,DIN,and 5-OH-IMI in serum were significantly positively correlated with oxidative stress.Overall,the amount of NEOs present in conjugated forms in human serum was determined to document the existence of a considerable proportion of free forms of these insecticides.

生物炭对新烟碱类农药的吸附性能与环境应用评估

农药的广泛高剂量使用对生物产生严重的毒性作用,造成严重的土壤污染和水污染。农药污染问题日益突出,迫切需要经济、有效的农药污染土壤修复处理技术加以解决。生物炭具有比表面积大、孔隙度高、吸附能力强等特点,可以吸附污染土壤中的农药,改善土壤状况,是一种具有广阔应用前景的生物材料。近年来,人们通过制备改性生物炭来提高生物炭的理化性能和吸附性能,为生物炭的应用开辟了新道路。详细阐述了生物炭的特性、新烟碱类农药的危害、生物炭对新烟碱类农药的吸附以及生物炭再生方法,以期为修复新烟碱类农药污染提供一定的参考和指导。此外,通过比较生物炭再生方法,为今后选择经济、有效、简便的生物炭再生应用提供参考。

超高效液相色谱串联质谱法测定豇豆中新烟碱类农药残留

本研究建立了超高效液相色谱串联质谱法(UPLC-MS/MS)同时检测豇豆中9种新烟碱类杀虫剂的多残留分析方法。豇豆样品用QuEChERS方法前处理,用Kinetex Biphenyl色谱柱分离,以甲醇和含0.1 mmol/L甲酸铵、0.001%甲酸的水作为流动相进行梯度洗脱,使用超高效液相色谱串联质谱检测分析。定量限为0.01 mg/kg,标准工作曲线在0.001~1 mg/kg范围内表现出良好的线性关系,决定系数(R^( 2))均大于0.99。目标杀虫剂在豇豆中的平均回收率为66.9%~109.8%,相对标准偏差为1.2%~10.0%。应用该方法对某地16个农贸市场中采集的71份豇豆样本进行检测,所有样品均符合我国所规定的豇豆(或豆类)中的最大残留限量标准要求。该方法简便、准确、灵敏度高,适用于新烟碱类杀虫剂在豇豆中的残留监测。

金属卤化物CH_(3)NH_(3)PbBr_(3)钙钛矿量子点快速检测新烟碱类农药

以新烟碱类农药为靶标物,结合荧光传感策略构建了基于金属卤化物钙钛矿量子点CH_(3)NH_(3)PbBr_(3)(Perovskite quantum dots,PQDs)荧光探针快速检测新烟碱类农药的新方法。该方法的线性检测范围为0.0~20 mg/L,相关系数为0.9939,检出限和定量限分别为0.17 mg/kg和0.56 mg/kg。对萝卜和香蕉样品中噻虫胺的加标回收率在79.3%~115.4%之间,日内日间相对标准偏差在3.8%~9.4%之间。该方法具有高灵敏度、高选择性和适用性,为农产品中新烟碱类农药残留的风险防控提供了一种有效的检测技术。对噻虫胺与钙钛矿量子点之间的相互作用进行了研究,结果表明,钙钛矿量子点与噻虫胺之间的相互作用是一个动态过程,噻虫胺对钙钛矿量子点的荧光猝灭方式为通过氢键或范德华力形成了新的复合物的静态猝灭。其内容可作为其他光谱分析手段的技术基础,其分析检测结果可为果蔬安全监管提供有价值的建议。

N-苯基八元氧桥环新烟碱化合物的合成及其增效活性

杀虫剂增效剂是提高杀虫剂杀虫效果和降低抗药性的关键成分。本文对具有特异性增效活性的八元氧桥环结构进一步衍生,设计合成了15个新型的N-苯基八元氧桥环新烟碱化合物,并测试了目标化合物与吡虫啉联用时对苜蓿蚜Aphis craccivora的致死率。结果表明:在1 mg/L质量浓度下,大部分目标化合物能使吡虫啉对苜蓿蚜的毒力增加,表现出增效作用,其中苯环上无取代的化合物4a和4-CF3取代的化合物4m增效活性相当,其对吡虫啉毒力的增效倍数分别为3.44和3.58,可作为候选化合物进一步研究。

分散液液微萃取/超高效液相色谱-串联质谱法测定环境水中7种新烟碱类农药

建立了巴氏滴管辅助的分散液液微萃取(PTD-DLLME)结合超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定环境水中7种新烟碱类农药的方法。该方法首次以巴氏滴管作为萃取容器,低密度低毒性的乙腈作为萃取剂,丙酮为分散剂。采用BEH C_(18)(2.1 mm×50 mm,1.7μm)色谱柱分离,0.01%甲酸水溶液(含2 mmol/L甲酸铵)和0.01%甲酸乙腈溶液(含2 mmol/L甲酸铵)为流动相梯度洗脱,电喷雾离子源(ESI)正离子方式扫描,多反应监测(MRM)模式监测,以保留时间和特征离子定性,外标法定量。在最优实验条件下,目标化合物在0.05~100μg/L范围内线性关系良好,相关系数(r2)不低于0.996,检出限(LOD)为0.02~0.1μg/L,定量下限(LOQ)为0.05~0.2μg/L,富集倍数为10倍。在1倍、2倍和10倍LOQ 3个加标水平下,各待测物的回收率为75.3%~116%,日内相对标准偏差(Intra-RSD,n=6)为2.7%~8.2%,日间相对标准偏差(Inter-RSD,n=3)为3.1%~10%,基质效应为-0.18%~6.66%。采用该方法对20批环境水样进行检测,其中1批河水样品中检出吡虫啉与噻虫啉,其浓度低于LOQ。该方法具有便于操作、富集效果好、回收率稳定、绿色环保以及成本低廉的优点,为环境水样中新烟碱类农药的检测提供了一种全新的解决方案。

噻虫嗪对蜜蜂健康影响研究进展

新烟碱类杀虫剂被广泛用于防治作物病虫害,然而过度使用导致的药物残留始终是一个不容忽视的问题,如噻虫嗪(Thiamethoxam)在我国主要蜜源植物油菜、棉花等的广泛应用,对授粉昆虫健康带来严重威胁。本文通过综述近几年噻虫嗪对蜜蜂采集飞行能力、生殖能力、生理免疫能力的相关研究,以及其与环境因子协同作用对蜜蜂健康所造成的潜在危害,强调了未来应加速研发高效防治靶标害虫以及对蜜蜂低毒或无毒的高选择性杀虫剂,以保障授粉昆虫安全。

无锡市市售蔬菜中新烟碱类杀虫剂残留分析及膳食风险评估

目的调查无锡市市售蔬菜中新烟碱类杀虫剂残留情况,评估其膳食暴露风险。方法采集2023年无锡市共7类20种74份市售蔬菜样品,采用超高效液相色谱-串联质谱法检测12种新烟碱类杀虫剂残留量,依据GB 2763—2021《食品安全国家标准食品中农药最大残留限量》分析检出和超标情况,通过相对效能因子模型、食品安全指数法、危害物风险系数进行膳食风险评估。结果新烟碱类杀虫剂检出率为39.19%,超标率为1.35%。检出5种新烟碱类杀虫剂,分别为吡虫啉、啶虫脒、呋虫胺、噻虫胺、噻虫嗪,检出率最高为噻虫嗪(21.62%)。7大类蔬菜均检出新烟碱类杀虫剂残留。平均总暴露浓度(IMIRPF)为0.980 mg/kg。相对效能因子模型中联合暴露浓度小于健康指导值,所有检出单一安全指数和总体安全指数均值均小于1,危害物风险系数R值中噻虫嗪为2.45,呈中度风险,其余杀虫剂R值均小于1.5,呈低度风险。结论本研究中发现无锡市市售蔬菜存在新烟碱类杀虫剂残留污染,尽管总体膳食风险较低,不会对一般人群造成不可接受的健康风险,仍需继续监测蔬菜新烟碱类杀虫剂。

三种药剂与球孢白僵菌对高粱蚜虫的协同控制作用

为评价烟碱类杀虫剂与球孢白僵菌的协同关系,明确吡虫啉、噻虫嗪、呋虫胺与白僵菌的相容性及二者复配对高粱蚜虫的杀虫效果,本研究利用生物活性测定方法,分别测定不同浓度的球孢白僵菌(菌株GZGY-1-3)和三种化学农药对高粱蚜虫的致死率。结果表明,不同浓度(1.6×10^(5)~1×10^(9)孢子/mL)的球孢白僵菌对蚜虫的校正死亡率为34.22%~89.90%。三种化学农药对高粱蚜虫的杀虫效果由高到低为吡虫啉,呋虫胺,噻虫嗪。通过化学农药和球孢白僵菌的复配,研究农药浓度和复配时间对球孢白僵菌孢子萌发率的影响,评价二者的相容性。结果表明,农药浓度越大,处理时间越长,对孢子萌发影响越大。用推荐农药剂量的1/8和1/10浓度处理后,菌药相容性较好,孢子萌发率均在90%以上。基于前期试验结果,测定菌药联合对蚜虫的杀虫效果。结果表明,菌药复配后的共毒系数均大于80,其对高粱蚜虫的致死率明显增高,表现为相加或者增效作用,其中,球孢白僵菌(4×10^(7)孢子/m L)与呋虫胺复配毒力最强,致死率达97.67%,共毒系数为135.37。因此,球孢白僵菌与三种烟碱类化学农药复配,当化学农药浓度稀释8倍以上,混合处理时间不超过4 h,二者的兼容性较好。球孢白僵菌(4×10^(7)孢子/m L)与呋虫胺复配效果最佳。

新烟碱类杀虫剂吡虫啉、噻虫啉和啶虫脒及代谢物在水稻及非靶标水生生物中的痕量检测方法及其应用

为了阐明新烟碱类杀虫剂对水稻和非靶标水生生物的残留特性和安全性,建立了水稻、非靶标水生生物斑马鱼Danio rerio和大型溞Daphnia magna、水体中3种新烟碱类杀虫剂(吡虫啉、噻虫啉、啶虫脒)及其7种代谢物的痕量检测分析方法。采用QuEChERS方法进行样品前处理,高效液相色谱-串联质谱检测,目标化合物均采用外标法定量。结果表明:10种目标化合物的溶剂标准曲线和基质标准曲线在1~1000μg/kg范围内线性关系良好,决定系数为0.991~0.999;10种目标化合物在6种基质中的平均回收率为71.16%~118.57%,相对标准偏差为0.54%~18.04%,水稻、斑马鱼、营养液和水中10种目标化合物的定量限为10μg/kg(大型溞中的定量限为50μg/kg),满足残留分析方法的要求。运用所建立的方法探究了3种新烟碱类杀虫剂在水稻及非靶标水生生物(斑马鱼和大型溞)中的吸收累积和代谢行为,结果表明这3种农药在水稻中的转运系数均大于7,极易向地上部分迁移;在非靶标水生生物中的富集系数均小于2 mL/g,为低富集性农药。

Design,synthesis and insecticidal activity of spiro heterocycle containing neonicotinoid analogs

Spiro heterocycles frequently occur in bioactive molecules. In the pursuit of neonicotinoids with spiro hererocycles, three types of novel neonicotinoids with spirobenzofuranone, spirooxindole or spiroacenaphythylenone framework were designed and synthesized. Insecticidal evaluation showed that some of spirobenzofuranone containing neonicotinoids exhibited moderate activity against cowpea aphid, armyworm or brown planthopper.