Study On Active Components Of Metabolites From Endophytic Fungus Of Ginkgo Biloba L.

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.