基于超分子作用的环糊精类导向农药载体的设计、合成及转运性能研究

The development and application of “guided pesticide” has provided an effective way to decrease the appliance of pesticide while keep the insecticidal efficiency. So far, the most common strategy for developing a guided pesticide is to conjugate an endogenous nutrient structure, such as glucose or peptides, to a pesticide compound via chemical reactions. However, the change of chemical structure of an existing pesticide will not only cause decreased bioactivity, but also lead to time consuming approving process before being commercialized. In this project, we would like to design and synthesize a series of cyclodextrin structures functionalized with amino acids as “guided pesticide carriers”, which can form stable host-guest complex with non-systemic and non-phloem mobile pesticides via supramolecular interactions, and take the pesticide towards specific target under the guidance of amino acid without changing its chemical structure. After applicable “guided carriers” were developed, the requirement and mechanism of host-guest complexes being transported in plant will also be investigated. The study will provide some new insights to the development of guided pesticides in the future.

当前“导向农药”的设计，一般是将糖、氨基酸等可被植物主动运输的内源性结构作为导向基团，对不具有输导性、内吸性的农药母体结构进行化学修饰，从而使农药分子在导向基团的介导下实现在作物体内的定向传输。然而，化学结构的改变不仅可能会影响农药效力，而且在推广前也需要进行冗长的新药审批程序。为解决此问题，本项目拟设计合成一系列使用氨基酸结构修饰的环糊精结构作为“导向农药载体”，使之能在超分子作用力的驱动下，与本身不能定向输导、定向积累的农药分子形成稳定的主-客体结构，并借助氨基酸导向基团在植物韧皮部定向输导。通过本项目的探索，期望能优化出一系列实用型导向农药载体，在保持农药分子化学结构不变的前提下对农药分子进行导向运载，并进一步探索主-客体复合物在植物体内被转运所需的条件及作用机制，为今后的导向农药发展提供新的思路。

本项目设计、合成并表征了一系列基于氨基酸导向结构的β-环糊精衍生物，通过对非内吸性农药茚虫威进行包合，制备了一系列氨基酸-β-环糊精/茚虫威包合物。通过测定包合物对小菜蛾的杀虫活性以及在植物（菜心、蓖麻）植株内吸收输导情况，筛选出了具有显著增效效果的异亮氨酸-β-环糊精偶合物，并通过荧光成像技术研究了其在植株根、茎部与小菜蛾肠道部位的吸收与分布规律，为探究其作用机制提供了依据。