Study On Secondary Metabolites Of Two Fungus Phaeosphaeriopsis Musae And Neoroussoella Sp.

In order to seek natural products with novel structure and significant activities,the secondary metabolites of a Morinda officinalis endophytic fungus Phaeosphaeriopsis musae A727 and a deep-sea-derived fungus Neoroussoella sp.FS526 were investigated,along with some of their biological activities like cytotoxic,antibacterial and enzyme inhibitory activity were evaluated in this papper.The above two strains of fungus were cultured by solid fermentation of rice and then extracted with ethyl acetate and concentrated into crude extract after fermentation finished.The extractions were isolated and purified by silica gel column,Sephadex LH-20 gel column and high performance liquid chromatography.The structures of compounds were identified and determinated by a series of modern spectroscopic methods like nuclear magnetic resonance（NMR）and high resolution mass spectrometry（HRESIMS）.Finally,26 monomer compounds（1-26）were isolated and identified from two strain,among with 9 new compounds,including 1 phenylhexanone derivative,1 benzopyranone derivative,5furanone derivatives and 1 pair of epimer.The known compounds contain polyketones,terpenes and phenol derivatives.Cytotoxic,antioxidant and enzyme inhibitory activities of some compounds were evaluated by SRB method and 96-well plate microdilution method.The results showed that the tested compounds had no significant activity against breast cancer cell line（MCF-7）,human liver cancer cell line（Hep G-2）,human lung cancer cell line（A549）and human glioblastoma cell line（SF-268）.Compound 18 performed significant antioxidant activities with IC₅₀ value of 14.95±0.72μM,which was similar to the positive control V_C,and compound 2 performed wellα-glucosidase activities with IC₅₀ value of 37.15±0.59μM.The secondary metabolites and biological activities of a plant endophytic fungus and a deep-sea-derived fungus were studied in this paper.Nine new compounds were isolated,one with significant antioxidant activity and one with strongα-glucosidase inhibitory activity were screened out,which enriched the chemical constituents of Neoroussoella genus and Phaeosphaeriopsis genus and provided a material basis and theoretical basis for the development and utilization of plant endophytic fungus and deep-sea-derived fungus.