民族药苦石莲抗流感的药效物质基础与作用机理研究

Traditional folk medicines play an important role in the fight against influenza outbreaks. The study on the effective substances and mechanism of them not only can obtain new anti-influenza agents but also can explain the scientific connotation for their efficacy in real terms. In our continous work, we have paid much attention on a classic anti-influenza herb, Caesalpinia minax Hance(called Ku Shi Lian in China), a species belonging to Fabaceae family. As a typical anti-influenza herb in Zhuang National Medicines，Ku Shi Lian has been used to treat influenza for hundreds years, and its mechanism and bio-active substances for its pharmaceutial effect were studied. C. minax was found with many ways on mechanism for anti-flu activity in our previous work for the first time, including showing the treatment effect on the pneumonia caused by virus infection,the significant inhibitory activity against influenza virus neuraminidase (NA) and having protective function for infected cells. Chemical study exhibited active fractions being rich in cassane diterpenoids. According to these results,we give a hypothesis for this project that Ku Shi Lian might have multi-ways for its anti-influenza mechanism, and the diterpenoids as the main effective components could show their anti-flu activity by the target protein NA way. In order to demonstrate the inherent scientificity of the theory, this project will continue to combine the chemical, pharmacological, analytical, and modern biological technologies, to study and elusidate the reasonable scientific connotation on the efficacy substances and mechanism of this folk medicine as a classic anti-flu agent, in addition, new anti-influenza leading compounds will be found during this process. Beside that, this project will achieve integrated research level for this national medicine, and also provide the valuable and important significance for the study of anti-flu drugs.

传统民族药在对抗流感爆发中发挥着重要作用，对其活性物质组成和作用机理研究即可寻找到新型抗流感药物又可揭示其独有的抗流感作用机制或靶点。项目前期以经典抗流感壮族药苦石莲为研究切入点，首次对其作用机制进行了探讨，发现苦石莲对病毒感染造成的肺炎有治疗作用，并对病毒感染细胞有保护功能，对高致病性流感病毒神经氨酸酶(NA)有明显的抑制活性，化学研究表明其富含卡萨烷型二萜组分群。为此项目提出假说：苦石莲存在多途径抗流感作用机制，其富含的二萜组分群是该药物发挥药效的重要物质基础，其中神经氨酸酶则是这类成分发挥药效的关键作用靶标。项目将继续结合中药化学、药物分析、现代生物技术等对该民族药抗流感的药效物质基础和机制做深入研究，以发现其所含的独特活性物质作用群和作用机理，从而阐明其用于抗流感的药效物质基础与作用实质，实现对该民族药研究的一体化，并可获得新型抗流感药物及先导结构，对抗流感药物研究具有重要现实义。

按照计划书在年度工作时间内对苦石莲抗流感病毒神经氨酸酶的活性物质基础做较深入研究，对其酶抑制活性做评价，获得初步的构效关系。 .天然药物苦石莲（Caesalpinia minax Hance）为云实属植物，民间用于治疗流感、毒蛇咬伤等症状，为系统从其发现新型的抗流感制剂，本课题从事了以下研究内容：.1. 以高致病性流感病毒神经氨酸酶（H5N1同源）抑制活性为抗病毒药物活性评价体系和作用靶点， 对传统药物苦石莲中抗流感病毒活性部位进行了活性追踪，发现其小极性组分CHCl3有较好的抑制活性，确定为活性部位之一。.2. 结合系统溶剂分离、制备型HPLC，Sephadex LH-20等分离纯化方法系统对活性部位的物质组成进行了研究，结合UV、IR、NMR、HR-MS、X-RAY、CD等谱学方法对单体成分进行了结构确证，以寻找并发现候选结构的前体。共分离32个化合物，鉴定了30个化合物的结构，24个为二萜衍生物，包括呋喃型卡萨烷二萜，呋喃内酯型卡萨烷二萜。其中新结构12个，属内首分5个，种内首分3个。Caesalmin C 在苦石莲中作为含量较高，活性较好的化合物，可作为一个用于定性、定量研究的指标成分。.3. 对卡萨烷衍生进行抗病毒神经氨酸酶活性评价，探讨其构效关系; 采用计算机辅助设计，结合QSAR设计模型及分子柔性对接，对活性最佳组分caesalmin C、7-acetoxybonducellpin C、caesalpinin F1为目标化合物，进行部分结构位点对接修饰，以适当引入新的官能团，进行虚拟筛选及活性预测, 获得以卡萨烷为母体的虚拟结构，包括醛基、羰基、-OH、苯环、含氮官能团等衍生物21个。