Studies On Antibacterial Secondary Metabolites From Two Deep-Sea-Derived Fungi

As land resources have been developed in large quantities,people have gradually turned their attention to the ocean with a mysterious veil.The ocean covers a large area,has a unique environment,and is rich in biological species.The number of microorganisms can account for90%of marine organism.As an important part of marine microorganisms,marine fungi are rich in secondary metabolites,with novel structures and significant biological activities,which are the important choice to search for drug leading compounds.In order to discover novel drug leading compounds,the secondary metabolites and their bioactivities of deep-sea fungi were carried out.The fungi were filtrated based on the TLC and HPLC chemical screen assays and experimental results of anti-bacteria and fungi by filter paper method.Thus,two active strains with abundant products and good resistance to bacteria and agricultural pathogenic fungi were obtained.Repeated extraction with ethyl acetate obtained a crude extract,and then 44 compounds were provided by using silica gel column chromatography,glucose gel column LH-20 column chromatography,C-18reverse-phase column chromatography,thin layer chromatography and high-performance liquid chromatography.The structures of these compounds were elucidated by modern spectral techniques?NMR,IR,UV,MS,X-ray,CD,etc.?,which include seven new compounds.The absolute configuration of the new compounds was determined by X-ray single crystal diffraction method,Mosher's method,circular dichroism?CD?and other methods.Fifteen compounds?1–15?were isolated from the strain Penicillium chrysogenum SCSIO 07007,including two new 3,4,6-trisubstituted?-pyrone derivatives?1,2?,and a new indole dione piperazine derivative?3?.And 29 compounds?16–44?were isolated from the strain Penicillium sp.SCSIO 41302,including one new benzopyran derivatives?16?,two new pyranone derivative?17,18?and one new benzene derivatives?19?,17 and 18 are enantiomers of each other.The antibacterial activiites and inhibitory activities of ACh E,glucosidase and PTP1B were evaluated.The results showed that the new compounds 1 and 2 showed significant inhibitory activity against PTP1B with IC₅₀ values of 9.32 and 27.8?g/m L,respectively.Compounds 20 and 25 showed significant inhibitory activities against staphylococcus aureus and methicillin-resistant staphylococcus aureus,with MIC values of 6.3/12.5 and 12.5/25.0?g/m L,respectively.In summary,the secondary metabolites of two strains of deep-sea fungi were studied in this paper.Seven novel compounds and thirty-seven known compounds were isolated and identified from Penicillium chrysogenum SCSIO 07007 and Penicillium sp.41302,and some compounds exbibited good biological activities,which enriched the structural types of secondary metabolites of marine fungi,and provide a scientific basis for the effective use and development of marine microbial resources.