Study On Secondary Metabolites Of Three Marine Fungi

30 marine fungi were isolated from the sea mud samples collected in the coastal waters of Shenzhen.After small-scale fermentation and cultivation,they were extracted with a mixed solvent(ethyl acetate: methanol=4:1)to obtain crude extracts.The crude extracts were tested for antibacterial activity against Staphylococus aureus and Candida albicans using disk diffusion method,and a total of 10 strains displayed inhibitory activity against to Staphylococcus aureus and 2 strains diaplayed inhibitory activity against Candida albicans.Combined with HPLC-MS profiles analysis,3 strains of fungi were identified as potential strains for further chemical investigations.MF180003 was identified as Paraphoma fimeti.14 compounds were isolated from the fermentation material of MF 180003 Paraphoma fimeti by using vacuum normal phase silica gel chromatography,Sephadex LH-20 chromatography and High Performance Liquid Chromatography.The structures were elucidated by mass spectrometry(MS),nuclear magnetic(NMR),calculated an experimental circular dichroism(CD)spectra,namely,7-hydroxyoospolactone(1),7-methoxyoospolactone(2),7-methoxy-9-hydroxyoospolactone(3),9-hydroxy-10-acetoxyoospolactone(4),9-R-6-dehydroxysescandelin(5),parapholactone(6),paraphamide A(7),Paraphamide B(8),paraphamide C(9),oospolactone(10),oospolactone methylether(11),10-hydroxyoospolactone(12),9,10-dihydroxyoospolactone(13),and oospoglycol(14).Compounds 1,2,3,4,5,6,7,8,and 9 are new compounds.MF180010 was identified as Penicillium cellarum.Two compounds were identified from the secondary metabolites of strain MF180010,which are 2,3-dihydro-5-hydroxy-8-methoxy-2,4-dimethylnaphtho[1,2-b]furan-6,9-dione(15)and 2-(2'-hydroxypropyl)-5-methyl-7-hydroxychromone(16).MF180022 was identified as Penicillium rotoruae.The compound fiscalin B(17)was identified from the secondary metabolites of strain MF180022.Compounds1,6,and 15 displayed antibacterial activity against Staphylococcus aureus,with minimum inhibitory concentration values of 12.5,12.5,and 200 ?g/m L,respectively.