Based on the similarities in the conformation of VS008（N-（4-methylphenyl）-3-（tert-butyl）-1-（phenylmethyl）-1H-pyrazole-5-carboxamide） and BYIO6830（N＇-（3,5-dimethylbenzoyl）-N＇-tert-butyl-5-methyl-2,3-dihydro-l,4-benzodioxine-6-carbohydrazide） bound to the active site of the EcR subunit of the ecdysone receptor（EcR）-ultraspiracle protein（USP） heterodimeric receptor,a series of new pyrazole amide derivatives were designed and synthesized.Their structures were confirmed by IR,~1H NMR,^（13）C NMR and elemental analysis.Results from a preliminary bioassay revealed that two of the pyrazole derivatives exhibited promising insecticidal activity.Specifically,compounds 6e and 6i exhibited good activity against Helicoverpa armigera（cotton bollworm） at low concentration.Symptoms displayed by tebufenozide-treated H.armigera were identical with those displayed by its treated counterpart.6i showed the same poisoning symptoms as those of tebufenozide.In addition,results from molecular docking result indicated that the binding modes of 6e and 6i at the active site of the EcR subunit of the heterodimeric receptor were similar to that of the bound tebufenozide.
Xi-Le DengLi ZhangXue-Ping HuBin YinPei LiangXin-Ling Yang
目的勘探广东湛江红树林植物内生放线菌多样性,为发现放线菌新物种和新抗生素奠定基础。方法样品经表面消毒后粉碎,10种不同培养基分离放线菌;通过PCR扩增、测定并比对16S r RNA基因序列,开展放线菌多样性分析;经发酵,离心,乙酸乙酯萃取上清液,旋转蒸发获得浓缩物,甲醇溶解制成样品;采用纸片扩散法对样品进行抗菌活性筛选;采用96孔板法,以秀丽隐杆线虫为对象,对样品进行杀线虫活性筛选;基于PCR的基因筛选技术初步探测活性菌株NRPS、PKS I、PKS II抗生素生物合成基因簇。结果经形态特征排重,从11份植物样品中共得到放线菌159株,16S r RNA基因序列比对分析表明,它们分布于8个目12个科19个属,其中链霉菌属为优势菌属,菌株IP4SC6为海藻球菌属潜在新种;发酵88株放线菌,发酵液乙酸乙酯萃取浓缩物测活结果表明,至少对一株检定菌表现为阳性的菌株有46株,总阳性率为52.27%,其中36株菌可能存在抗生素生物合成基因簇,8株可能同时具有3种抗生素生物合成基因簇;对秀丽隐杆线虫有较强杀虫活性的放线菌有3株,LC50值分别为83.2,132.0和138.0mg/m L。结论广东湛江红树林植物中存在多样性丰富的药用放线菌资源,具有从中发现放线菌新物种及新抗生素的潜力。
In order to discover highly active ecdysone analogs, a series of new substituted pyrazole amide derivatives were obtained using structure-guided optimization method and further screened for their insecticidal activities, in the basis of the core structures of the two active compounds N-（3-methoxyphenyl）-3-（tert-butyl）-1-phenyl-1H-pyrazole-5-carboxamide（6e） and N-（4-（tert-butyl）phenyl）-3-（tert-butyl）-1-phenyl-1H-pyrazole-5-carboxamide（6i）, previously presented by us. The chemical structures of the title compounds were identified by spectral analyses. The preliminary bioassay results indicated that one among the synthesized pyrazole derivatives, compound 34, endowed with good activity against Mythimna Separata at 10 mg/L, which was equal to that displayed by the positive control tebufenozide. In addition, examples of molecular docking and molecular dynamics studies demonstrated that 34 may be the potential inhibitor to Ec R and its docking conformation was similar to that of tebufenozide. In addition, increasing the hydrophobic effect and considering the suitable bulk effect on pyrazole ring are beneficial to the inhibiting activity to Ec R and activity in vivo.
Xi-Le DengJin XieYong-Qiang LiDe-Kai YuanXue-Ping HuLi ZhangQing-Min WangMing ChiXin-Ling Yang
