The Studies On Molecular Identification And Pharmaceutical Chemistry Of Endophytic Fungi From The Ecosystem Of Camptotheca Acuminata

Endophytes referr to fungi colonizing healthy plant tissues without causing symptom or apparent injury to the host. Reasearch results in near years show that endophytic fungi can produce some similar physiological active products to the host plant. So studies on the endophytic fungi and their metabolites have been a new way to find medical resources.In this paper, Camptotheca acuminata Decne., a Chinese endemic medicinal plant, was selected as material. The tissues distribution of endophytic fungi in C. acuminata and isolation method were preliminary studied. The result indicated that, the superficial disinfection for endophytic fungi isolation is better by 75% ethanol combined with 0.1% Hg₂Cl method. And the Hg₂Cl disinfection time is 4⁵min to C. acuminata's root and stem, for C. acuminata leaf's Hg₂Cl disinfection time should be controlled about 2min. Under this superficial disinfection condition, totally 70 endophytic fungi has been isolated. Mainly distributes in the leaf (42.9%) and the bark(35.7%), the number of endophytic fungi from root (14.3%) and seed (7.1%) to be few, has not been isolated from the xylem.The morphology and the molecular biology had been adopted to identify the endophytic fungi. 6 strains wereidentified into Genus level by morphology. All the endophytic fungi were divided into 27 morphotypes based on similar cultural characteristics, our method was to identify the morphotypes strains and determine its classified status based on phylogenetic analysis of ITS and 5.8S rDNA gene sequences, as well as sequence similarity comparison. Altogether obtained ITS sequences of 18 strains, the analysis result indicated that, this 18 endophytic fungi belong to 14 genera, 8 families, 8 orders, 4 classes, 2 phylums. The result of morphology and molecular biology was consistent. The identification result showed the biodiversity of endophytic fungi in the C. acuminata ecosystem at certain degree. At the same time, phylogenetic analysis based on ITS to endophytic Phomopsis was done. In this research, altogether obtained 18 Phomopsis strains, they are dominant strains account for 25.7%.Thin layer chromatography(TLC) method and the highly effective liquid chromatography(HPLC) were employed to detect metabolites of CZ-14, CZ-17, CZ-18. The results indicated the mycelium of this 3 strains may include camptothecine, 10-hydroxycamptothecine or similar compounds. The content is 0.03-0.04mg/g. The metabolites were fermentated on PDA liquid media with the juice from the camptotheca...