甲氰菊酯对大鼠格列喹酮口服吸收及肠道紧密连接蛋白表达的影响

目的 探讨甲氰菊酯(Fen)对大鼠格列喹酮(Gli)口服吸收及小肠组织紧密连接蛋白表达的影响.方法 将15只SD大鼠随机分为玉米油组、Gli组和Fen+Gli组.Fen+Gli组和Gli组分别连续ig给予Fen 3 mg·kg-1或等体积玉米油14 d后,ig给予Gli 15 mg·kg-1,给Gli 15 min后不...     

紫色非硫细菌GP-7基因文库的构建和新酯酶基因的克隆

目的筛选并克隆具备降解甲氰菊酯农药的新酯酶基因。方法通过建立紫色非硫细菌GP-7的基因文库,用酯酶快速筛选方法获取甲氰菊酯降解基因。结果从紫色非硫细菌GP-7的基因文库中筛选到一个新型酯酶基因序列Rhe8。该基因核苷酸序列大小为810 bp,包含269个氨基酸残基,其中有565bp序列片段与Rhodospirillum centenum SW基因组的酯酶基因片段有94%的同源性。结论通过初步测定,该酯酶具备降解甲氰菊酯的能力。     

Biodegradation of fenpropathrin by Rhodopseudomonas sp. strain PSB07‐21 cultured under three different growth modes

This study aimed at the biodegradation of fenpropathrin by Rhodopseudomonas sp. strain PSB07‐21 cultured under different growth modes. The biomass production, cell surface hydrophobicity and fenpropathrin biodegradation efficiency of the strain PSB07‐21 cultured under the photoheterotrophic growth mode were better than that shown by the strain PSB07‐21 cultured under the photoautotrophic or the chemotrophic growth mode. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis analysis using cell‐free protein extracts showed several distinct protein bands in the gels representing the strain PSB07‐21 cultured under the photoheterotrophic growth mode. The fenpropathrin enzymatic degradation was clearly affected the bacterial growth mode. Results obtained from this study should improve our knowledge regarding fenpropathrin biodegradation under field conditions. Our findings can also be used to optimize the usage of Rhodopseudomonas sp. PSB07‐21 in field applications.     

Development of an enzyme-linked immunosorbent assay for the pyrethroid fenpropathrin

An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for the detection of fenpropathrin was developed. Two haptens, FPa (α-carboxy-3-phenoxyphenyl-2,2,3,3-tetramethyl-cyclopropane-carboxylate) and FPb (α-(N-butyrical)-3-phenoxybenzyl-2,2,3,3-tetramethyl-cyclopropane-carboxylate), were synthesised and conjugated with ovalbumin (OVA) by the mixed anhydride method as coating antigens (FPa–OVA and FPb–OVA), and the hapten FPb was conjugated to bovine serum albumin (BSA) by the carbodimide method to produce an immunogen (FPb–BSA). Polyclonal antibody against fenpropathrin was raised for screening the more sensitive coating antigen. Under optimised assay conditions, the 50% inhibitory concentration (IC₅₀) was 0.34±0.090 mg/L and the limit of detection (LOD) was 0.0093±0.00065 mg/L. The cross-reactivities with other pyrethroids, such as deltamethrin, cypermethrin, fenvalerate and cyhalothrin, were all lower than 0.1%. Water samples spiked with different concentrations of fenpropathrin (0.01–1.0 mg/L) were analysed according to this method. The ic-ELISA developed could successfully be applied to residue analysis of fenpropathrin in aquatic.     

Collaborative contribution of six cytochrome P450 monooxygenase genes to fenpropathrin resistance in Tetranychus cinnabarinus (Boisduval)

Cytochrome P450 monooxygenases (P450s), as an important family of detoxification enzymes, participate in the metabolism of agrochemicals in almost all agricultural pests and play important roles in the development of insecticide resistance. Two P450 genes (CYP389B1 and CYP392A26) were identified and their expression patterns were investigated in our previous study. In this study, four more P450 gene sequences (CYP391A1, CYP384A1, CYP392D11 and CYP392A28) from the Clan 2, Clan 3 and Clan 4 families were identified and characterized. Quantitative PCR analysis showed that these four P450 genes were highly expressed in a fenpropathrin‐resistant (FeR) strain of Tetranychus cinnabarinus. In addition, their expressions were much more sensitive to fenpropathrin induction in the FeR strain than the susceptible strain. Gene‐silencing experiments via double‐stranded RNA feeding were carried out. The results showed that mRNA levels of these six P450 genes were reduced in the FeR strain and the activities of P450s were decreased. Consequently mite susceptibilities to fenpropathrin were increased. Interestingly, silencing all six P450 genes simultaneously had an even greater effect on resistance than silencing them individually. This study increases our understanding of the molecular mechanisms of insecticide detoxification, suggesting that the overexpression of these six P450 genes might play important roles in fenpropathrin resistance in T. cinnabarinus collaboratively.     

甲氰菊酯人工抗原的合成和鉴定

目的 合成与鉴定甲氰菊酯的人工抗原.方法 通过水解、酰化、酯化等反应合成了甲氰菊酯的半抗原2,2,3,3.四甲基环丙烷羧酸-a-(N-丁酸基)-甲酰氨-3-苯氧基苄酯(Ⅳ)和2,2,3,3-四甲基环丙烷羧酸-a-羧基-3-苯氧基苄酯(Ⅲ).通过碳二亚胺法将半抗原Ⅳ与牛血清蛋白(BSA)偶联制备免疫抗原,通过混合酸酐法将半抗原Ⅲ与卵清蛋白(OVA)偶联制备包被抗原.结果 用质谱和核磁共振对Ⅲ和Ⅳ进行结构表征,合成产物为目标物.紫外光谱法鉴定结果表明,免疫抗原和包被抗原都发生了有效偶联,偶联比38:1和15:1,免疫抗原通过免疫新西兰大白兔得到的抗体效价为5.12×105.结论成功的合成了甲氰菊酯的人工抗原,为其免疫方法的建立奠定了基础.     

Effect of Natural Dissolved Humic Material on Bioavailability and Acute Toxicity of Fenpropathrin to the Grass Carp,Ctenopharyngodon idellus

The effects of aquatic humic acids on the bioconcentration and acute toxicity of fenpropathrin were evaluated using grass carp,Ctenopharyngodon idellus, in laboratory freshwater systems. The results demonstrated that both bioavailability and acute toxicity decreased in the presence of aquatic humic acid 5 and 10 mg/liter. In addition, the extent of influence increased with increasing concentration of aquatic humic acid.     

固相萃取-高效液相色谱法测定桔梗中拟除虫菊酯的农药残留

目的:建立桔梗中甲氰菊酯、高效氯氟氰菊酯、溴氰菊酯、氰戊菊酯、氯菊酯、联苯菊酯共6个拟除虫菊酯类农药残留的提取、净化及其残留量测定的方法。方法:样品运用石油醚提取,商品CARB/NH2小柱净化,乙腈-二氯甲烷(5∶95)洗脱,HPLC-DAD检测。色谱条件:采用Hypersil BDS C18(250 mm×4.6 mm,5μm)色谱柱,流动相为乙腈-水(70∶30),流速1 mL.min-1,检测波长230 nm。结果:样品4水平添加时的6个拟除虫菊酯类化合物回收率在75.63%～107.5%范围内,RSD在2.3%～9.9%范围内,可以满足农药残留分析的要求。结论:该方法灵敏度高,选择性强,操作简单、快速,净化效果好。可应用于桔梗药材中痕量农药残留的检测。