| Ocean takes up almost 71% of the entire surface of the earth, and the unique, complex ecological environment provide an important support for a diversity of marine-derived microorganisms. According to researchers, fresh Enteromorpha prolifera can apparently inhibit four kinds of red tide micro algae's growth, and the methanol extracts of dried powder of E. prolifera can significantly inhibit their growth either. Besides, scientists have discovered that endophytic fungus may produce the same or similar compounds as their hosts. However, the study on endophytic fungi of E. prolifera has rarely been reported until now. Therefore, this dissertation focused on the purification and secondary metabolites of fungi associated with E. prolifera. We isolated 9 fungi from E. prolifera collected from the First Swimming Beach in Qingdao. And their chemo-diversity and cytotoxicity were studied by integrated TLC, HPLC and bio-assay method. Strain HT-2 was selected for further studyThe fermentation of strain HT-2 was successively extracted with ethyl acetate. From the crude extracts, thirteen compounds 1~13 were isolated by repeated column chromatography on silica gel, Sephadex LH-20 and RP-18, followed by reverse-phase semi-preparative HPLC and recrystallization. By means of spectroscopic method such as MS, 1D-NMR and 2D-NMR, and their physicochemical properties, seven compounds were identified as Preechinulin (1), Polanrazine A(2), Neoechinulin A (3), neoechinulinB(4),(Z)-6-((2-(2-methylbut-3-en-2-yl)-1H-indol-3-yl)methylene)pipera zine-2,3,5-trione(5),3-(1H-indol-3-ylmethyl)-6-methyl-,(3R,6R)-2,5-Piperazinedione(6),VariecolorinH(7),2,5:2',5'-dide(epidithio)-3,3'-didemethyl-19,19'-dideoxy-19,19,19',19'-tetramethyl-, (2,2',5,5')- (9CI) Chaetocin(8),Tetrahydroauroglaucin(9), Isodihydroauroglaucin(10),and Dihydroauroglaucin (11), respectively. |
