Studies On The Chemical Constituents Of Four Plant Endophytic Fungi And Their Bioactivities

Plant endophytic fungi are an important microorganism and establish a mutualistic symbiosis relationship.They can live in the tissues or organs of health plant and won’t cause the diseases.The biodiversity of plant endophytic fungi and communication mechanism with host based on the metabolites lead to multiple kinds of secondary metabolites with great broad bioactivities from the plant endophytic fungi.This Thesis is composed of five chapters.The studies on the culture broth of endophytic fungus Ilyonectria robusta from Bletilla striata,solid cultures of endophytic fungus Ilyonectria sp.from Bletilla striata,and the culture broth of endophytic fungus Tullasnella sp.from Dendrobium wangliangii and endophytic fungus Fusarium tricinctum from Coptis chinensis.were introduced in the first four chapters.And the fifth chapter summarized pimarane diterpenes and their bioactivities from fungi.In this thesis,the compounds were isolated and purified by several methods,including normal phase silica gel column chromatography,reverse phase column chromatography,sephadex column chromatography,medium pressure preparative liquid chromatography,and high performance liquid chromatography;The compounds were identified by several modern spectroscopic methods,including ¹H NMR,¹³C NMR,HMQC,HMBC,COSY,ROESY,CD,IR,UV,optical rotation,and X-ray single crystal diffraction.56 compounds were isolated and identified from above four endophytic fungi,including 16 new compounds.The types of these compounds consist of diterpene,alkaloid,pyrrole derivatives,harzianic acid derivatives,chromone,anthraquinone,naphoquinone,and others.These compounds were assayed for their immunosuppressive activity,anti-inflammatory activity,and inhibitory activity against Candida Albicans.Bletilla striata is herb of Orchidaceae.Its dried tuber is traditional chinese medicine.Ilyonectria robusta belongs to genues Ilyonectria,which is a new genus established in 2011.From the culture broth of this fungus,18 compounds were isolated,including 9 new compounds.The types of new compounds comprise diterpene and pyrrole derivative.Two new compounds,robustaditerpene C and E,showed immunosuppressive activity and one known compound tryhistatin showed anti-inflammatory activity after evaluated.Another endophytic fungus Ilyonectria sp.from Bletilla striata also belongs to genus Ilyonectria.16 compounds were isolated from the solid culture of this fungus,including 6new compounds.The main types of new compounds consist of harzianic acid derivatives and chromones.Dendrobium wangliangii is a special specie of Orchidaceae.It is an endemic group in the Yunnan section of the dry hot valley of the Jinsha River and has potential value in medicine and ornamental.The fungus Tullasnella sp.has ability to promote the germination of host plant seeds.From the culture broth of this fungus,12 compounds were isolated,including one new compound,Tullasnellachromone.It showed moderate inhibitory activity against Candida Albicans and Escherichia coli.Coptis chinensis is a plant of Ranunculaceae.Its dried tuber is traditional Chinese medicine.10 known compounds were obtained from the culture broth of the fungus Fusarium tricinctum.They mainly contain sterols and cyclic dipeptides.Fungi are one important resource of natural products.Diterpenes from fungi possess various scaffolds and bioactivities.Pimarane diterpenes were mainly isolated from plants and fungi,but they weren’t systematically summarized.The fifth chapter of this thesis reviewed pimarane diterpenes from fungi,including their structures,bioactivities,and biosynthetic pathway.