菖蒲属中药抗老年性痴呆7H-AI7O有效成分及作用机制研究

Senile dementia is also known as Alzheimer’s disease (AD)，which is a neurodegenerative disease characterized by cognitive impairment. Currently, about 46.8 million patients are diagnosed with AD worldwide, but there are no effective drugs to cure or control the disease. Our research team found a novel tropoloisoquinoline alkaloid (TA) named neo-tatarine with the unique mother nucleus, 7H-azuleno[1,2,3-i,j]isoquinolin-7-one (7H-AI7O), from Acorus calamus L., which can significantly inhibit the death of PC12 cells caused by Aβ25-35. However, due to its few plant sources and low yield, further research was shelved. Based on the theory proposed by Silverton that there are correlations between TA and azafluoranthene alkaloids (AA) in plants, we take 7H-AI7O as the research object, and the UPLC-Q-TOF/MS2 method will be applied to systematically characterize and guide discovery and separation of 7H-AI7O in Acorus plants. Then, we use AA and 2-methoxy-3-acetyl-cycloheptatrienone as the starting materials to synthesize 7H-AI7O derivatives through the structural modification of A ring and D ring of 7H-AI7O. Meanwhile, we conduct and detect the blood-brain barrier permeability on Wistar rats and related indicators on APP/PS1 transgenic mice of 7H-AI7O derivatives, to clarify structure-activity relationship and the possible mechanism of 7H-AI7O derivatives in anti-senile dementia. The research provides theoretical basis for design and mechanism study of new 7H-AI7O drugs.

老年性痴呆又称阿尔茨海默病(AD)，是以认知功能减退为主要症状的神经退行性疾病，全球约有4680万AD患者，目前尚无有效治愈或控制该病的药物。项目组从水菖蒲中发现以7H-薁[1,2,3-i,j]异喹啉-7-酮(7H-AI7O)为母核的环庚三烯酮异喹啉生物碱(TA)——菖蒲新碱，其显著抑制Aβ25-35诱导的PC12细胞死亡，但因植物来源少、含量低，阻碍其深入研究。基于Silverton提出的TA和荧蒽生物碱(AA)具有相关性的假说，本项目以7H-AI7O为研究对象，采用UPLC-Q-TOF/MS2系统表征和指导菖蒲属中药7H-AI7O的发现和分离；分别以AA和2-甲氧基-3-乙酰基-环庚三烯酮为原料，经A和D环结构修饰合成一系列的7H-AI7O衍生物；通过对Wistar大鼠血脑屏障通透性，及对APP/PS1小鼠相关指标的检测，明确7H-AI7O抗AD的构效关系和相关作用机制，为新型7H-AI7O药物设计和机理研究提供理论依据。

本项目研究内容包括（1）以菖蒲新碱（neo-tatarine）为参照，建立了54个7H-AI7O化合物的质谱信息数据库；建立了菖蒲属中药7H-薁[1,2,3-i,j]异喹啉-7-酮（7H-AI7O）成分群的富集和UPLC-Q-TOF/MS2快速检测方法；结合7H-AI7O化合物数据库，监测并分析了不同产地石菖蒲和水菖蒲中7H-AI7O成分群，明确7H-AI7O化合物在水菖蒲和石菖蒲中均有分布，水菖蒲中7H-AI7O种类及分布较石菖蒲丰富。（2）确定7H-AI7O化合物8-甲氧基-7H-薁[1,2,3-i,j]异喹啉-7-酮的合成路线，以3-羟基-4-甲氧基苯甲酸甲酯（3-羟基-4-甲氧基苯甲醛）为原料，经硝基化，苄氧基化，酯键水解（羧基化）和酰氯化等反应，生成关键中间体3-苄氧基-4-甲氧基-2-硝基苯甲酰氯；再与苯乙胺反应，经缩合、Bischler-Napieralski、Pschorr环化和Pd/C脱氢等反应，生成7-羟基-8-甲氧基-茚并[1,2,3-ij]异喹啉-7-醇，并经D环氧化、亲核环丙烷化和电子重排制得；确定7H-薁[1,2,3-i,j]异喹啉-7-酮合成关键中间体2-氨基-3-氯酰基-环庚三烯酮的合成工艺，以环庚三烯酚酮为原料，经引入卤素，羧酸化，酰氯化，羟基甲氧基化，甲氧基氨基化等反应制得。（3）研究核心内容“菖蒲属7H-AI7O衍生物”获得国内外发明专利2项，neo-tatarine等8个7H-AI7O化合物及其在预防、处理、治疗或减轻由受损神经细胞引起的疾病的药物中的用途为专利保护范围。本项目的研究，不仅从植物来源和合成角度，为解决7H-AI7O植物来源少、含量低和结构单一等制约中药发展的瓶颈问题，提供了科学依据，而且为菖蒲开窍醒神物质基础研究提供新思路，为进一步开发具有自主知识产权、国际领先水平的老年痴呆治疗新药，奠定了坚实的理论基础。