谷氨酸介导溴代吡咯腈对茶树重要隐蔽害虫的输导活性

Under the financial support from the National Natural Science Foundation of China, new tralopyril-glutamic acid conjugate A with phloem mobility and systemic insecticidal activity against Dendrothrips minowai Priesner was screened out for the pupurs of controlling cryptic pests on tea with a lower dose by improving bioavailability of pesticide that could be applied in tea plantation. This application project aim taking the conjugate A as the model, to design and synthesize its analogs and test their phloem mobility and systemic insecticidal activity. The caster bean seedlings are employed to study the phloem mobility of conjugates. Systemic insecticidal activity assay against two kind cryptic insects of D. minowai Priesner and Aleurocanthus camelliae Kanmiya & Kasai is to be performed by using the methods of smearing leaves. Based on the analyzes results of their relationship between structure and activity as well as structure and translocation by using the Kleier model and Rule of Five, the potential conjugates with high transport property and systemic insecticidal activity are to be found out. The phloem mobile mechanism of the selected potential conjugates were further studied through methods of configuration-effect relationship and competitive inhibition. The successful project execution is expected to provid novel strategy for the control of cryptic pests on tea by developing of new insecticides with well bioavailability. Thus enrichs the theories of plant pharmacology.

为了改善茶树适用农药生物利用度而实现非采收季节低用药量防治茶树隐蔽害虫，项目申请人在已结题国家自然科学基金项目的资助下，研究筛选出了1种具韧皮部输导性且对茶棍蓟马具输导杀虫活性的谷氨酸溴代吡咯腈偶合物A。本申请项目拟以偶合物A为模板，设计合成其系列类似物。然后采用蓖麻体系研究新合成系列偶合物的韧皮部输导性；运用涂叶法研究其对茶棍蓟马和黑刺粉虱2种隐蔽性茶树害虫的输导性杀虫活性；根据韧皮部输导性和输导性杀虫活性研究结果，运用Kleier模型和“Rule of Five”，探讨其结构与韧皮部输导性和结构与输导性杀虫活性之间的关系，筛选出输导性杀虫活性优异的具潜在应用价值的偶合物；最后采用构型-效应关系法和竟争抑制法进一步研究并明确其韧皮部输导机理。通过本项目研究，可为开发具良好生物利用度的新型茶园适用杀虫剂而防治茶树隐蔽性害虫提供思路和方法；进一步丰富农药植物药理学理论。

为了改善茶树适用农药生物利用度而实现非采收季节低用药量防治茶树隐蔽害虫，本研究项目，溴代吡咯腈为母体，以谷氨酸为导向基团，采用点击化学的方法，设计并合成系列谷氨酸-溴代吡咯腈偶合物；开展了输导性、药害、杀虫活性、虫体内的代谢、结构效应关系分析和输导机理等系统研究，取得了如下研究结果。.设计合成了14个含炔溴代吡咯腈中间体Q1-Q14，从中筛选出1个中间体Q1，构建了9种不同碳链长度的Boc-L-谷氨酸-溴代吡咯腈偶合物2B-10B；经进一步脱保护合成了9个茶谷氨酸-溴代吡咯腈偶合物2C-10C。研究明确了偶合物2C-10C、2B和3B相的韧皮部输导性；证明了偶合物2C-10C对茶树不具药害作用；研究明确了Q1-Q14对小菜蛾的活性，其中Q1的杀虫活性最好，其LC50值为0.0203 mM；研究明确了偶合物2C-10C对小菜蛾的杀虫活性，其中以偶合物2C-5C较好，24h的LC50值分别为0.240、0.441、0.440和 0.460mM；偶合物2C和3C在小菜蛾体内可代谢为溴代吡咯腈，其处理后的检测量分别为0.5950和0.3172nmol/kg；偶合物2B和3B对小菜蛾的LC50值分别0.0475和0.0879 mM。0.2g/L浓度偶合物2B和3B静电喷施后，对茶棍蓟马均表现较好防效，药后3天的防效达72%以上。.分析明确了Q1-Q14的结构与杀虫活性，以3碳炔Q1的活性最好；明确了碳链长度影响偶合物2C-10C的杀虫活性，未脱保护的偶合物2B和3B的杀虫活性要优于脱保护偶合物2C和3C。结构与输导性分析结果初步表明，碳链长度影响偶合物2C-10C的韧皮部输导性，其中碳链为3的偶合物3C最高；未脱保护的偶合物2B和3B的输导性要明显低于脱保护偶合物2C和3C。根据“Rule of five”规则、Kleier数学模型和构型法研究结果，推断转运蛋白可能参与了偶合物2C-10C的长距离运输，偶合物2C-10C存在被动扩散以外的载体介导的吸收转运机制；初步明确相关转运载体蛋白参与了偶合物2C和3C的韧皮部输导性。.通过本项目研究，获得了2个新发现，提出了新理念：矢量化前体杀虫剂，发展了农药生物利用度控制理论。发现未脱保护偶合物2B和3B比脱保护偶合物2C和3C更具深入研发前景。研究结果对安全有效防治茶树隐蔽性害虫的药剂研发具指导意义和实践意义。