牛蒡子苷元衍生物杀灭鱼类单殖吸虫定量构效关系及其杀虫机理研究

The study of natural active compounds is one of the important means to develop new pollution-free aquatic drugs, control aquaculture diseases, and also guarantee the security of food and environment. This application is focused on the arctigenin and other lignans, specifically determining the functional groups with parasiticidal activity and toxicity groups to fish and also making a clear relationship between these two groups through the research of the structure-activity relationship which can be achieved by the synthesis of arctigenin and its derivatives and detection their parasiticidal activity. Quantitative structure-activity relationship models (QSAR) are also established to predict the parasiticidal activity of the synthetic compounds for the sake of setting up a fast and feasible method for the design, prediction and screening of the lignan parasiticides. Electron microscopy and proteomics technology are applied to find the targets of the screened active compounds. At the same time,HPLC and LC-MS methods are used to evaluate pharmacokinetics parameters of target molecules in fish for the investigation of the metabolism and residual mechanisms. This research not only lays the academic foundation for the development of lignan drugs against fish parasites, but also provides new ideas for the innovation and creation of base for the pollution-free fishery drugs in the future, which has an important application prospect.

天然产物活性及其构效关系研究是药物研发的理论基础，也是创制无公害水产新药、控制水产养殖病害发生、保障食品与水环境安全的重要途径之一。本项目拟对牛蒡子苷元及其系列衍生物进行合成，结合药效学测定，探究其构效关系，从而确定杀虫活性相关功能基团和对鱼致毒基团；结合合成化合物杀虫参数建立QSAR模型进行理论验证，并建立快速可行的木脂素类杀虫药物分子设计预测和筛选方法；针对合成的牛蒡子苷元及筛选的高活性分子，采用超微组织技术、蛋白质组学技术等探索药物对指环虫的作用靶标、密切相关的蛋白及相关基因，初步揭示木脂素类杀虫药物的作用机理；采用HPLC和LC-MS等方法研究高活性分子在鱼体内的代谢动力学，探讨代谢规律和残留机制。该研究的开展不但为研发鱼类寄生虫木脂素类药物奠定理论基础，同时也为今后无公害渔药基础创新与创制提供新思路和模板，具有重要应用前景。

本项目以香草醛为反应起始化合物，通过基团保护、取代反应、氢化还原等反应合成了牛蒡子苷元。整个反应共分为8个步骤，其中有4步反应的反应产率达到100%，提高了牛蒡子苷元的合成产率。同时，对反应中一些价格比较昂贵的试剂进行了替换，有效的降低了反应的成本。另外，我们对合成的牛蒡子苷元进行了杀虫机理研究。扫描电镜观察表明随着处理时间和浓度的逐渐加大，指环虫体表变得粗糙，粘液增多，甚至破裂，导致体液外流。这种超微结构的变化与我们之前在光学显微镜下观察到的有的虫体处于裂解状态，体内基质外泄的现象是一致的，这可能是导致指环虫死亡的原因之一。