蕊木和奶子藤中生物碱类化学成分及其生物活性评价

	蕊木和奶子藤中生物碱类化学成分及其生物活性评价
	陈谌
导师	张于
关键词	夹竹桃科 Apocynaceae 蕊木 Kopsia arborea 奶子藤 Bousigonia mekongensis 单萜吲哚生物碱 Monoterterpene indole alkaloids 生物活性 Biological activity
摘要	天然产物因其结构多样性和生物活性多样性是创新药物研究中先导化合物设计的重要模板，单萜吲哚生物碱（monoterpenoid indole alkaloids，MIAs）是天然产物类群中成药性比例较高的一类，因含有高度复杂的多环骨架以及显著的生物活性而备受关注。本课题组前期在夹竹桃科植物中发现一系列具有新颖骨架且在调控溶酶体功能及相关疾病（神经退行性疾病等）活性优异的MIAs，为进一步拓展MIAs成分的结构多样性并挖掘活性分子，本论文选取富含MIAs的夹竹桃科两种植物蕊木属蕊木（Kopsia arborea）和奶子藤属奶子藤（Bousigonia mekongensis）为研究对象，进行了系统的生物碱化学成分研究，针对其中的MIAs进行了生物活性评价。以蕊木的种仁为研究对象，综合使用多种分离手段和谱学技术等方法从中分离鉴定18个MIAs，其中5个为新化合物，结构类型包含白坚木替宁类、白坚木类以及MIAs二聚体。化合物1-3是首例发现的通过亚甲基单元连接的白坚木替宁-白坚木类型二聚体，化合物4和5为白坚木替宁型生物碱。细胞实验显示1-3对CDK5激酶表现出显著的抑制作用（IC50：0.34-2.18 μM），并能降低pCDK5（Tyr15）、pTau（Thr217）和pTau（Ser396）的表达水平，通过分子对接实验发现化合物1的酰胺羰基与CDK5的LYS89残基、3的酯羰基与GLU12残基之间分别形成的氢键可能是其发挥作用的关键因素，这些结果表明化合物1-3对AD具有潜在的防治作用。以奶子藤的种仁和枝叶为研究对象，综合使用多种分离手段和谱学技术等方法从中分离鉴定了51个生物碱类化合物，包含柯南因-士的宁类、长春曼胺类以及其他类型生物碱。对分离的化合物和课题组前期发现的系列化合物，共计168个，进行了促溶酶体生成活性的筛选，发现6个生物碱（化合物23，24，31，32，81和83）可以较好地促进溶酶体生成，针对代表性化合物24和81进行进一步的研究，通过qRT-PCR、瞬时转染等方法发现其不影响溶酶体生成的主要调控因子TFEB和TFE3，通过RNA-seq发现81能显著激活内质网中蛋白生成相关的PERK信号通路，推测其可能是通过诱导内质网应激促进TFEB/TFE3非依赖性自噬和溶酶体的生物发生。; Natural products are important templates for the design of leads in innovative drug research due to their structural complexity and variability. Monoterpenoid indole alkaloids (MIAs) are a group of natural products with a high proportion of druggability and are of great interest because of their highly complex polycyclic skeletons and significant biological activities. Our group has identified a series of MIAs with novel skeletons and excellent activity in the regulation of lysosomal function and related disease (neurodegerative disease, etc.) in the Apocynaceae family. In order to expand the diversity of MIAs, explore the active molecules, two plants of family Apocynaceae, Kopsia arborea and Bousigonia mekongensis, were selected for carrying out a systematic study on the chemical composition of alkaloids as well as its biological activity. The fruits of K. arborea used as research objects. By comprehensive using various separation methods and spectrum technologies, 18 alkaloids including five new ones were isolated from the fruits of K. arborea. Compounds 1-3 were three undescribed aspidofractinine-aspidosperma-type monoterpenoid indole alkaloid dimers linked by a methylene bridge. Compounds 4 and 5 were aspidofractinine-type monoterpenoid indole alkaloids. The cellular assays showed that 1-3 exhibited significant inhibiton of cyclin-dependent kinase 5 (IC50: 0.34-2.18 μM) and reduced the expression levels of pCDK5 (Tyr15), pTau (Thr217) and pTau (Ser396). Molecular docking studies found a hydrogen bond formed between the amide carbonyl group of 1 and the LYS89 residue of CDK5, and between the ester carbonyl group of 3 and the GLU12 residue, respectively, may be the key factor for their activity. These results suggested 1-3 have a potential role in the prevention and treatment of AD. The kernels, leaves and branches of B. mekongensis used as research objects. By comprehensive using various separation methods and spectrum technologies, 51 alkaloids mainly including yohimbine, eburnean were isolated and identified from the kernels, leaves and branches of B. mekongensis. A total of 168 including the isolats and a series of compounds discovered by the group earlier, were evaluated for lysosomal generating activity, and six ones (compounds 23, 24, 31, 32, 81 and 83) showed strong lysosomal generating activity. Compounds 24 and 81 were selected for further machanisms. By cell transfection and qPT-PCR, it was found that they did not affect transcription factors TFEB/TFE3. Moreover, 81 can significantly activate the PERK signaling pathway related to the protein processing in endoplasmic reticulum, and it is speculated that it may be promoted TFEB/TFE3 independent autophagy and lysosomal generating by inducing endoplasmic reticulum stress.
语种	中文
	2022-11
学位授予单位	中国科学院大学
文献类型	学位论文
条目标识符	http://ir.kib.ac.cn/handle/151853/75235
专题	昆明植物所硕博研究生毕业学位论文
推荐引用方式 GB/T 7714	陈谌. 蕊木和奶子藤中生物碱类化学成分及其生物活性评价[D]. 中国科学院大学,2022.

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