Studies On The Secondary Metabolites And Their Activities Of Several Marine Fungi And Actinomycetes

After a long evolutionary process,marine microorganisms gradually adapt to the special environment of high pressure,low temperature and high salinity.The study of secondary metabolites of marine microorganisms has become a new research hot spot of natural products.In this study,marine fungi were isolated from algae in the coastal area of Zhoushan and hydrothermal vent sediments in Kuishan island,Taiwan.Actinomycetes were isolated from sediments in the East China Sea.Secondary metabolites were separated and purified by ODS column chromatography,normal phase chromatography,semi-preparative and preparative high performance liquid chromatography.The structures of the compounds were identified and analyzed by NMR,MS and other modern spectral analysis methods.Four strains of marine microbes were selected as research objects,including Penicillium sp.H7-5(marine algae endophytic fungi),Alternaria sp.TQ-67(endophtic fungus from Suaeda glauca),Aspergillus sp.DQ-13(hydrothermal sediment from Kuishan island,Taiwan)and Penicillium sp.Z-M-1(marine endophytic fungus).Twenty-nine compounds were isolated and extracted from the extract by large-scale culture and fermentation,three of which were new compounds named pyrrospirone J(4),pyrrospirone K(7),chrysogenamide M(10).As natural products,the structures of compound 1,3,4,5,7,8,9 are rare and contain ether,benzene,pyrrolidone,and ketone functions.By using the OSMC method,two compounds phenol A(30)and 3-methoxyfuran-2-carboxylic acid(31)were isolated from actinomycete H-1003,which were different compounds obtained by the previous metal stress methods.In addition,eight compounds isolated from TQ-67 and four compounds isolated from YQ-13 were tested for antibacterial and antioxidant activities.In which aspermutarubrol(11),sydowiol D(12),sydowiol E(13)possess good antioxidant activities.Compounds leporin A,chaetominine have obvious antibiotic activity,and compounds 3-hydroxy-2-(2-hydroxy-6-methoxy-4-methyl-benzoyl)-5-methoxy and 1,2-seco-trypacidin showed weak antibiotic activity,but antioxidant activity was not obvious.Compounds 1,2-seco-trypacidin and 3-hydroxy-2-(2-hydroxy-6-methoxy-4-methylbenzoyl)-5-methoxy showed weak antibiotic activity,but no obvious anti-oxidation activity was observed.