Studies On The Secondary Metabolites Of Marine Fungi From The Mangrove Plant In Yangjiang

Mangrove refers to the growth in tropical and subtropical coast intertidal zone, inundated by periodic tide, as the main body is evergreen shrubs or trees of the tidal flat wetland woody biological communities in Mangrove plants。It is rich of particular features microbial groups, produce a variety of physiological active substances taxa, and the production of secondary metabolites。Due to the effection of high salinity, high strength, light, the mangrove microbial secondary metabolites has tremendous difference in biosynthesis pathway and the enzyme reaction system, compared with the ordinary terrestrial microorganisms。Living in this particular environmentment, therefore it has produced many new structure diversity, bioactive secondary metabolites significantly, provides rich active compounds for the screen of anti-tumor, antibiotic, antioxidant drug。Random amplification polymorphism (RAPD) technique analysis fungus2-2Y and2-3G, found that the two strains with great aspergillus homology。This thesis mainly about the study on the antimicrobial activity of the122strains of medicinal mangrove rhizosphere soil of symbiotic fungi and endophytic fungi of the Hongguang-village of Guangdong-yangjiang mangrove forest, and study on secondary metabolites of fungi which with good antimicrobial activity。122strains were isolated from the medicinal plants of roots、stems、leaves、bark and the soil samples of the plant rhizosphere in15～20cm of Aegiceras corniculata、Kandelia candel、white lotus、Bruguiera cylindrica and Acanthus ilicifolius。20strains of biological activity metabolites screened from the antimicrobial activity experiment by E.coli、Staphyloccocus aureus、Micrococcus luteus、Salmonella、Bacillus subtilis and White staphylococcus。The minimal inhibitory concentration (MIC) value and minimum bactericidal concentration (MBC) value of extracts fom Ethyl acetate were determinated,22strains with good antimicrobial activity were screened.On this basis, preliminary screening of the fungi secondary metabolic structure type, with the method of thin layer chromatography (TLC), strains of2-2Y were expand trainded。With the guide of antimicrobial activity, eight active compounds were isolated from2-2Y, they were austinol(1),cytochalasin H (2),2-hydro-acetyldehydroaustin(3), 1,2-tetrahydro-acetyldehydroaustin (4), asperfuranone(5), Asperterpenoid A (6), ergosterol(7), ergokonin B(8)。Three compounds were isolated from strains of2-3G。Search found that2-hydro-acetyldehydroaustin(3),1,2-tetrahydro-acetyldehydroaustin (4), asperfuranone(5) are new compounds,Austinol (1) has a good inhibiting the activity of e. coli, asperfuranone (5) has a medium to restrain activity of RAW cell lines, IC50value is19.8microns o...