靶向鳞翅目害虫的虎耳兰活性成份石蒜碱及其衍生物的合成和杀虫活性及构效关系研究

We have found that lycorine alkaloid from Haemanthus albiflos jacq. possesses excellent insecticidal activities against lepidoptera pests such as diamondback moth (Plutella xylostella), beet armyworm (Spodoptera exigua), pieris rapae (Linne), and spodoptera litura (Fabricius) and so on. Moreover, insecticidal action mode of lycorine is similar to pymetrozine. Based on the above result, we will focus on total synthesis and insecticidal activity and structure-activity relationships of lycorine alkaloid and its derivatives. We will explore several new, simple and practical synthetic routes to preparation of lycorine alkaloid and its derivatives with good overall yields. At the same time, we will present structure optimization and synthesize different types of lycorine derivatives for bioactivity evaluation. All of the synthesized compounds would be tested on their insecticidal activities against such important agricultural lepidoptera pests as oriental armyworm (Mythimna separata), beet armyworm, diamondback moth, pieris rapae, cotton bollworm (Helicoverpa armigera), corn borer (Ostrinia nubilalis), and et al., respectively. Then we will summarize structure-activity relationship and look for pharmacophore, further we will study on correlation among indoor toxicity and field efficacy and chemical structure, which is very helpful for carryying out further structural optimization and finding optimized compounds with simpler structure and higher insecticidal activity. Moreover, their heat and light stability and water solubility will be studied. Further study of pesticide formulation of the optimized compounds is very necessary. Finally, we will employ fluorescence polarization method to study the action mechanism by testing the binding affinity of these synthesized compounds to transient receptor potential (TRP) ion channel complex.

本项目在前期首次发现从虎耳兰中分离的石蒜碱对小菜蛾、甜菜夜蛾、菜青虫、斜纹夜蛾等鳞翅目害虫具有很好的杀虫活性和杀虫作用方式类似于吡蚜酮的基础上拟进行石蒜碱及其衍生物的合成方法学和杀虫活性及构效关系研究。将探索原料易得、步骤短、收率高、条件温和、实验操作简单的新路线合成石蒜碱及其衍生物；对其结构广泛修饰和优化，包括取代基和骨架的改变；研究目标化合物对我国难以防治的粘虫、甜菜夜蛾、小菜蛾、菜青虫、棉铃虫、玉米螟等重要农业鳞翅目害虫的杀虫活性和构效关系，系统研究田间防效、室内药效与化学结构三者的相关性，进一步指导新活性分子的设计；进行活性物质的稳定性和溶解性及剂型研究；将通过荧光偏振的方法来研究目标化合物与昆虫瞬时感受器电位（TRP）的钙离子通道的亲和力。该项目的立题密切结合我国的实际，期望创制具有我国自主知识产权的易于合成的有开发价值的新型高效安全的绿色杀虫剂，具有重要的理论和实际意义。

本项目拟进行石蒜碱及其衍生物的合成方法学和杀虫活性及构效关系研究，四年来已完成任务书规定的研究内容，达到了预期研究目标。发现石蒜碱对小菜蛾的杀虫活性（LC50=10.6mg/L）好，要高于加兰他敏、小檗碱、鱼藤酮和苦参碱的活性，石蒜碱对蚊幼虫也表现出很好的活性，忽地笑乙醇提取物在200g/hm2和石蒜碱在100g/hm2对小菜蛾的防效和氟铃脲在60g/hm2的防效相当，石蒜碱还表现出较好的抗烟草花叶病毒和抑菌活性（辣椒疫霉，EC50=7.76mg/L），确定了石蒜碱是忽地笑球茎农药活性的主要物质。发展了石蒜碱衍生物的高效合成新方法20多个，实现了可见光催化下由醛或酮以及非活化卤代烷烃对氮杂芳环的直接烷基化，通过可见光诱导的2,3位双取代吲哚的去芳构化、氰基化、羟基化、氧化，合成了多官能团化的螺或并氮杂环。通过石蒜碱C1和C2位羟基的衍生和改造、C环双键的还原、C环芳构化和D环开环以及甲撑基的开环等方法，对石蒜碱进行结构多样性衍生和农药活性及构效关系研究，优化出结构简单的菲啶类化合物，具有很好的抗TMV活性和杀虫活性以及广谱的抗植物病原菌活性，进一步合成了菲啶酮、菲啶、菲啶氮甲基季铵盐类化合物，发现表现出了很好的抗TMV活性，和宁南霉素活性相当，利用Schneider提出的骨架跃迁策略，把菲啶类化合物含氮6元环扩大为7元环，转变为二苯并杂䓬类化合物，优选化合物的抗TMV与宁南霉素相当，作用机制研究表明该化合物可诱导TMV 20s disk不规则聚集从而抑制TMV组装。在本学科国际知名期刊Sci. Adv.、Chem. Sci.、Green Chem.、Org. Lett.、Chem. Commun.、J. Agric. Food Chem.、Pest Manag. Sci.等发表49篇标注SCI收录论文；授权中国发明专利7项和欧洲发明专利2项以及美国发明专利1项，新申请中国发明专利14项和美国发明专利1项。项目实施以来毕业博士6名、毕业硕士10名，其中陈琳伟和谢佳林获得南开大学优秀硕士学位论文，汪清民教授二次获“南开大学优秀硕士学位论文指导教师称号”，青年教师宋红健博士荣获“第四届赵善欢奖学奖教基金”优秀青年学术奖。汪清民教授受邀报告5个；项目组四位年轻教师和博士生硕士生也积极参加国内外学术会议，做了大会报告或口头报告4个。