Isolation Of Endophytic Fungus From Four Medical Plants And Study Their Metabolites

The rich natural products contained in medicinal plants can be used to treat a variety of diseases,and most medicinal plants contain endophytic fungus.Many studies have shown that the symbiotic relationship between endophytic fungus and plants makes endophytic fungi could produce active components which were same or similar as those of plants.For this reason,we isolation and purification endophytic fungus from four midicinal plants and study on its bio-activities.The aim of this thesis is to obtain natural products with certain biological activity.The research contents and results are as follows:1.Isolation and purification of endophytic fungu:totally 20 endophytic fungus strains in roots,steams,leaves and flowers was seprated and purified from Euonymus phellomanus.,Salvia przewalskii.,Acanthopanaxsenticosus.and Hypericum ascyron..Among them,10 strains were from Hypericum ascyron.,2 strains were from Acanthopanaxsenticosus.,6 strains were from Salvia przewalskii.and 2 strains were from Euonymus phellomanus..Bio-activities detection:80 extracts were obtained by liquid fermentation technology（in PDB medium and CYM medium）,ethyl acetate extraction and methanol reflux extraction methods.Monoamine oxidase inhibitory activity,acetylcholinesterase inhibitory activit,PI3K inhibitory activity,and antibacterial activity of these extracts were evaluated.Extracts from strains SJ-2、WJ-3、HJ-3showed monoamine oxidase inhibitory activity with IC₅₀ of 126.64、118.56、221.34μg/m L.However,other extracts showed no notable bio-activities in above detection.2.Chemical constitutent research:Eight compounds were isolated from endophytic fungus WJ-3 and SJ-2 by TLC,macroporous resin column chromatography,MCI column chromatography,silica gel column chromatography,high performance liquid chromatography.The structure of isolated compounds were identified by spectral data analysis.Finally,6 compounds were were identified as3-methyl-6,8-dihydroxyisocoumarin（1）、Dibutyl phthalate（2）、Ergosterol peroxide（3）、Enniatin B（4）、Monomethylsulochrin（5）、Fumitremorgin C（6）.Compound7 was too little to identify and the structure of the compound 8 was the same as that of the compound 2.3.Identification of endophytic fungus:20 endophytic fungus strains were identified by morphological characteristics and DNA sequence similarity.DY-1 was identified as Epicoccum sp.;DY-2 was identified as Phoma sp.;DY-3、SJ-1、DJ-2、DG-1、WY-1、Hh-1、HG-1、HG-2、HJ-1、HJ-2、HJ-3、HJ-4、HY-1 and HY-3 were identified as Alternaria sp.;Hh-3 was identified as Botrytis sp.;SJ-2 was identified as Fusarium sp.;WJ-3、DJ-1 was identified as Penicillium sp..