新型香豆素类化合物的设计、合成、抗单殖吸虫活性及构效关系研究

Using pharmacology activity molecules from nature products as leading compounds, the discovery of green fishery drugs with computer aided drug design protocols is one of significant ways to control parasite diseases in aquaculture and guarantee the safety of food and environment. In this research, Dactylogyrus intermedius, a representative of the monogeneans, was chosen as the research model. Based on the previous research, nature pharmaceutical molecule with high insecticidal efficacy-osthole was selected as a lead compound, and 176 coumarin derivatives were synthesized through various chemical reactions, such as substitution reaction, 1,3-dipolar cycloaddition reaction and multicomponent reaction. After the evaluation of anthelmintic activity (EC50) and acute toxicity against fish (LC50), 3D-QSAR model and pharmacophore model will be respectively to build using chemical structural parameters and bioactivity data. Based on those models, the rules of quantitative change between chemical structures and bioactivity can be expounded and it also can explain how the type of chemical group and the conformation of the groups to responsible for the anthelmintic activity and acute toxicity against fish. Then, some compounds with higher anthelmintic activity and lower toxicity were synthesized according to the guidance of the model. This research not only offer a theoretical basis for the development and pharmacological study of novel drugs against monogeneans, but also provide some references for development of other anti-parasite drugs in aquaculture. This project has the significance of theory and application.

以天然产物中的活性分子为先导化合物，借助计算机辅助药物设计方法研发无公害渔药是解决水产寄生虫病害、保障食品和环境安全的重要途径之一。本项目在前期研究基础上，以中型指环虫为研究对象，通过取代反应、1,3-偶极环加成反应和多组分反应等手段对高杀虫活性天然化合物-蛇床子素进行结构改造，合成得到176个香豆素类化合物。评价其杀虫活性（EC50）和对鱼类的毒性（LC50）；利用生物信息学手段，对化合物的结构参数和活性数据进行分析，构建三维定量构效关系模型（3D-QSAR）和药效团模型，阐明化合物结构与杀虫活性之间的量变规律，确定杀虫或致毒基团的种类及空间构象；根据模型指导，设计并合成新型高效低毒的杀灭单殖吸虫活性分子。该项目的研究不仅能对开发杀灭单殖吸虫新药提供理论基础和依据，也能为其他种类水产药物的研发提供借鉴和参考，具有重要的科学意义和应用前景。

寄生虫感染会导致淡水养殖以及海水养殖鱼类大量的死亡，寻找价格低廉、环境友好的治疗药物一直是水产养殖领域的研究热点。本项目中，我们通过Witing反应、Pechmann缩合反应、Wiiliamson醚化反应及1,3-偶极环加成反应合成得到7-氨基-4-甲基香豆素类以及香豆素-三氮唑类化合物，通过Biginelli反应合成得到香豆素-嘧啶类化合物以及色烯-甲腈类化合物。通过质谱、核磁共振氢谱和碳谱等手段确定所合成化合物结构的正确性。随后，对所合成化合物进行了抗单殖吸虫活性测定，结果表明：合成得到的香豆素类化合物中70%以上化合物在不同的药物浓度下均表现出了对中型指环虫的不同程度的杀虫活性。通过相关数据，我们成功构建CoMF模型，明确在香豆素母环结构中的吡喃环结构，或者苯环的7位或8位区域引入大体积基团或者富电子基团能够有效的提高化合物的杀虫活性。根据模型的指导，我们合成了几个新型香豆素类化合物，并通过测定其杀虫活性验证了模型的稳定性与准确性。我们通过对7-（1-对甲苯磺酰基-1H-1，2，3-三氮唑-4-基）甲氧基香豆素（N11）的杀虫机制研究发现：N11可以导致寄生虫表皮结构损伤，如表皮褶皱增多、出现孔状破损、瘤状结构增多等，同时，N11可以通过影响寄生虫的呼吸系统，如降低寄生虫体内ATP浓度等途径起到杀虫作用。对7-氨基-4-甲基香豆素类化合物抗SVCV活性研究表明：7-N-对甲苯磺酰胺基-4-甲基香豆素（LMC1011）可以通过提高SVCV感染的鲤鱼上皮瘤细胞的细胞活力、抑制病毒复制、增强鱼体干扰素相关抗病毒基因表达量等途径，在宿主层面发挥抗病毒作用。本项目研究创制了多个生物活性小分子，有助于完善水产养殖行业寄生虫病和病毒病的防治体系，具有一定的科学意义和应用价值。