The Secondary Metabolites And Biological Activity Of Endophytic Fungi G8 From Walnut

An fungus G8 was screened from the root of walnut, the identification experiment whether the fungus is endophyte have been done, the result showed that the fungus was endophyte, and the method separating endophyte from walnut is feasible. The work which identified the endophyte have been carried according to the shape and the character of micro-structure, and confirmed it as Coniothyrium. vitivora Mitura initially.The 8 stains of pathogen and 3 kinds of plant was used as the materials to test the activity of the endophytic fermentation , result showed that the fermentation of the endophyte G8 had some inhabitation to the 8 strains, and the rate of inhabitation was over 50% to the Helminthosporium turcicum Pass and Fusarium graminearum, it indicate that the fermentation have some compounds to reduce the pathogen; the fermentation had effect on the 3 kinds plant, the inhabited rate of the bud was rape>mung>radis, and the inhabited rate of root was mung>radis>rape, the inhabited rate of mung was highest of all. so the endophyte G8 was screened as the material to study.G8 was fermented largely. The extract of its fermentation was tested to inhabit 28strains pathogen and also the ethyl acetate extract of it to 5 kinds of bacteria. The results showed that (1) For the extract of acetyl acetate, butanol and residue. The different extracts of fermentation all have different range activity to 28 kinds of pathogenic fungi. At concentration 40mg.mL-1, the inhabited effect of the phases is ethyl acetate, butanol and residue from strong to weak, but the inhabitation of butanol extract is better than the two other phases to Thanatephorus cucumeris, Dothiorella gregaria and Monographella nivialis. (2)Different concentrations of ethyl acetate extract have been measured to 11 kinds of pathogenic fungus. The results show the inhabiting rate of the extract is 100% to Physalospora piricola, Valsa mali miyabe et, Cochliobolus sativus and Magna porthe. The inhabited rate of Colletotrichum hum trifolii, Fusarium graminearum, Alternaria solani, Glomerella cingnlata.schr.et.and Bipolaris maydis to different concentration have been obvious difference. (3)The extract of ethyl acetate had studied on inhabited effect of 5 species bacteria. Bacillus megaterium and Bacillus mesenterius is sensitive to drugs, but not dominant to different concentration. The section of the secondary metabolites was sure through the test , also the density of inhabitation and the pathogen needed to test from the result (2).The fermentation of the endophyte was carried, the extract of ethyl acetate was 31.2g. two compounds was separated following its activity, passing the silica gel column chromatography, passing Sephadex LH-20 column chromatography and re-crystallizing. The structure of the compound was elucidated through physical and chemical properties and spectrum data. One of them is cholesterol, and the other wasn't elucidated.