【作者】 易大为；

【导师】 何建勇； 白秀峰；

【作者基本信息】 沈阳药科大学 ， 微生物与生化药学， 2003， 硕士

【摘要】 内生真菌长期生活在植物组织内部，与宿主协同进化，在演化过程中二者形成了互惠共生的关系，在宿主的生长发育和系统演化过程中起重要作用。内生真菌可产生一些重要的治疗人类疾病的药物，对内生真菌次级代谢产物的研究，可以筛选得到一些结构新颖、活性专一的物质。本文以银杏树内生真菌（Endophytic fungus of Ginkgo biloba L., EG）为研究对象，通过对内生真菌胞内产物的研究，定向筛选银杏内酯产生菌。 首先，从原始菌种EG₃出发，在筛选过程中分离得到菌株G_3-1、G_3a、G_3b、G_AR、G_AY、F_1-3和F₃，其中菌株G_3b、G_AR、G_AY、F_1-3和F₃经菌种鉴定，被归属为半知菌亚门、丝孢纲、瘤座孢目、瘤座孢科、镰孢菌属（fusarium）。 应用高效液相色谱法和电喷雾质谱法以及液相质谱联用技术，以银杏内酯标准品为对照，对G₃系列菌株的胞内产物进行了筛选和检测。由检测结果初步认定，菌株G_3b和F₃的代谢产物中含有银杏内酯A、银杏内酯B和白果内酯。 在菌株F_1-3的发酵液中，检测到有抗革兰阳性菌的物质存在，通过对活性成分的追踪，分离得到化合物F1-3A和F1-3B。经过质谱、¹H谱、¹³C谱以及二维核磁共振波谱的测定和解析，确定化合物F1-3A的分子结构为： cyclo[Hiv-Me-Val-Hiv-Me-Val-Hiv-Me-Val]；质谱、¹H谱及¹³C谱的数据与环肽类抗生素Enniatin B的文献值基本一致，认定二者同质。经过质谱测定和解析，化合物F1-3B可能与Enniatin B₁或Enniatin D同质。更多还原

【Abstract】 There exists symbiosis between Endophytic fungus of plants and their hosts, now that Endophytic fungus live in botanical tissues for a long period of time, and evolve together with their hosts. Endophytic fungus play important roles in the growth and evolution of plants, and many of them can produce some compounds with novel structure and specific bioactivity. In this paper, Endophytic fungus of Ginkgo biloba L.(EG) were studied, from which the ginkgolide-producing strains were screened orientationally, by means of studying endo-cellular metabolites from trial-strains.First of all, strains G3-1, G3a, G3b, GAR, GAY, F1-3 and F3 were obtained from primitive strain EG3, in the course of screening. Moreover, strains G3b, GAR, GAY, F1-3 and F3 were identified as Deuteromycotina,Hyphomycetes,Tuberculariales, Tuberculariaceae, fusarium sp.Besides, the endo-cellular metabolites of the all strains were detected and screening, based on the analysis methods in which samples were compared with authentic Ginkgolides by HPLC and ESI-MS. Thus, it may be concluded that ginkgolide A, ginkgolide B and bilobalide occur in metabolites of strains F3 and G3b.Meanwhile, the substances against Gram-positive bacteria were discovered in culture broths of F1-3. After further isolation and purification, compounds F1-3A and F1-3B were obtained from active extracts. The chemical structure of F1-3A was determined to cyclo[Hiv-Me-Val-Hiv-Me-Val-Hiv-Me-Val] by several structure analysis methods, such as ESI-MS, 1H-NMR,13C-NMR and 2Dimensional-NMR, etc. F1-3A shared the same NMR and MS spectral data with cyclodepsipeptide Enniatin B reported. F1-3B was regarded as Enniatin B1 or Enniatin D according to the analysis of MS.更多还原