四株内生真菌和一种植物的化学成分及其生物活性研究

发布时间：2017-12-27 05:27

本文关键词：四株内生真菌和一种植物的化学成分及其生物活性研究　出处：《山东大学》2017年博士论文　论文类型：学位论文

【摘要】：植物内生真菌(Endophytic fungi)是指一类在一定阶段或全部阶段均生活在健康的组织和器官内部,而不使宿主表现出明显病害症状的真菌。并且在与宿主长期协同进化的过程中,它们产生了许多活性优异和结构新颖的次生代谢产物,受到了天然产物化学家们的关注。植物内生真菌作为丰富的真菌基因多样性宝库,为人们发现可持续的、结构新颖和活性多样的先导化合物提供了重要来源。所以针对一些特殊群体(如以苔藓和地衣为宿主)内生真菌的次生代谢产物研究具有重大的意义。本文对四株植物内生真菌(包括一株苔藓内生真菌和三株地衣内生真菌)和一种传统药物植物向天果的化学成分进行了系统研究。根据前期活性筛选的结果选择了 Aspergillus fumigatus、Phialocephala fortinii、Phaeosphaeria avenariaf sp.和Ulospwra bilgamii这四株内生真菌使用大米培养基进行放大发酵。分别使用乙酸乙酯和甲醇对菌株发酵产物和向天果进行提取,采用硅胶柱色谱、葡聚糖凝胶Sephadex LH-20柱色谱、ODS柱色谱以及高效液相柱色谱等多种分离纯化技术,从四株内生真菌和一种植物中共分离得到78个化合物,其中包括32个新化合物。综合采用质谱、核磁共振、单晶衍射和圆二色谱等方法确定了化合物的平面结构和立体构型。对分得的化合物进行细胞毒、抗真菌和α-葡萄糖苷酶抑制等活性评价,结果显示部分化合物具有显著的活性,其中化合物25和30与氟康唑联用具有很好的逆转耐药活性。进一步活性机制研究表明,化合物25和30通过抑制基因MDR1的表达来抑制外排泵的活性,进而实现逆转耐药。
[Abstract]:Endophytic fungi is a kind of fungus that lives in healthy tissues and organs at a certain stage or at all stages, but does not make the host show obvious symptoms of disease. And in the process of long-term co evolution with host, they have produced many secondary metabolites with excellent activity and novel structure, which have attracted the attention of natural product chemists. Endophytic fungi, as a rich repository of fungal diversity, provide an important source for finding sustainable, novel and active lead compounds. Therefore, it is of great significance to study the secondary metabolites of endophytic fungi, such as moss and lichens. The chemical constituents of four endophytic fungi, including a bryophyte endophytic fungus and three lichen endophytic fungi, and a traditional medicinal plant, "Tian Tian Guo", were systematically studied in this paper. According to the results of previous active screening, four endophytic fungi, including Aspergillus fumigatus, Phialocephala fortinii, Phaeosphaeria avenariaf sp. and Ulospwra bilgamii, were selected for amplification and fermentation using rice medium. The fermentation products were extracted and used to fruit ethyl acetate and methanol, separation and purification by silica gel column chromatography, Sephadex Sephadex column chromatography, LH-20 ODS column chromatography and high performance liquid chromatography and other fungi, and a plant in a total of 78 compounds were isolated from four strains, including 32 new compounds. The plane structure and stereotyping of the compounds were determined by mass spectrometry, nuclear magnetic resonance, single crystal diffraction and circular two chromatography. The activity of the obtained compounds was evaluated by cytotoxic, antifungal and alpha glucosidase activities. The results showed that some compounds had significant activity. Compound 25 and 30 combined with fluconazole had a good reversal of drug resistance. Further studies have shown that compounds 25 and 30 inhibit the activity of the efflux pump by inhibiting the expression of gene MDR1 and then reverse the drug resistance.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R284

【参考文献】