Study On Metabolites Of Two Symbiotic Fungi

This paper select two symbiotic fungi to study on their secondary metabolites. To separate and purify the chemical constituents, many chemical methods were used, such as silica gel column chromatography, preparative thin-layer chromatography, gel filtration chromatography, recrystallization and so on. Structures of compounds were identified by extensive spectroscopic analysis. Some of the compounds were tested on the antifungal activity and antioxidant activity.According to screening the antifungal activity in the twenty strains endophytic fungi using the disk diffusion method, seven stains belonging to the Pestalotiopis showed the certain activity. One strain of the seven was Pestalotipsis virgatula which were cultured by solid state fermentation for the further research. In the research of the chemical constituents from the strain, twelve compounds were obtained:p-hydroxybenzaldehyde,5,8-peroxidergost-6,22-diene-3β-ol,(3β)-stigmast-5-en-3-ol, p-hydroxybenzeneethanol, dibutyl phthalate, diisobutyl phthalate,3-(4-hydroxy-3-methoxyphenyl) acrylic acid,17-(5,6-dimethylhept-3-en-2-y1)-10,13-dimethyl-2,3,4,9,10,11,12,13,14,15,16,17-dodecahydro-1H-cyclopenta[a] phenanthren-3-yl palmitate,4-hydroxyphenethyl acetate,(22E,24R)-ergosta-7,22-dien-3β,5α,6β-triol,5,8-peroxidergost-6-ene-3β-ol, sitost-4-en-3-one. The tested compounds were not show the antifungal activity by means of micro-dilution assay by contrast with positive control.Twelve compounds were obtained from entomopathogenic fungus Paecilomyces sp. after solid state fermentation. The compounds were7-hydroxy-5-methoxy-4,6dimethylisobenzofuran-1(3H)-one,5-hydroxy-7-methoxy-6-methyl-1-oxo-1,3-dihydroisobenzofuran-4-methanal,5-(1-hydroxyethyl)-2-(hydroxymethyl)-4H-pyran-4-one, nicotinic acid, ethyl-4-hydroxy-6-methoxy-2,3-dimethylbenzoate,1-methyl-2-pyrolidone, butanedioic acid, kojic acid,2-(5-(3-hydroxybutyl) furan-2-yl) acetic acid,1-H-indole, D-glucopyranosyl-D-fructofuranose, D-glucopyranosyl-D-fructopyranose. Some of the compounds were tested antioxidant activity by means of DPPH method. Kojic acid, showing the higher free radical scavenging activity, had the antioxidant activity.