Studies On The Secondary Metabolites Of Three Mangrove Endophytic Fungi From South China Sea

In recent years, researches on secondary metabolites of marine microorganisms have become hotspots that domestic and oversea scientists pay much attention to. Marine microorganisms could produce numerous novel and bioactive compounds because of the complicated living environment and their peculiar metabolism. Mangrove-derived fungi are rich in resources and had a great capacity for producing bioactive metabolites, which make them the most systemically and roundly researched marine fungi in present.On the basis of several chromatography techniques and spectral methods, 3 species mangrove fungi SK3RW6M, ZZF42 and SKX1YW3G1 collected from South China Sea were studied on their secondary metabolites in this thesis. 15 Compounds including 2 new compounds with xanthone structure were isolated using thin-layer chromatography, column chromatography, Sephadex LH-20 and HPLC, characterized by MS, 1D NMR and 2D NMR. Compounds isolated from the culture medium and mycelium of fungus SK3RW6M are 6M-1(new), 6M-2(new), ergosterol, ergosterol peroxide and Mannitol. Xylopyridine A,methyl 14-methylpentadecanoate, stearic acid, methyl stearate and tetracosanoic acid were isolated from the culture medium and mycelium of fungus ZZF42. There are also 5 compounds isolated from the culture medium and mycelium of fungus SKX1YW3G1, including 5-butylpicolinic acid, methyl 5-butylpicolinate, 5-methylpyrimidine-2,4(1H,3H)-dione, 3,6-dibenzylpiperazine-2,5-dione and 3-benzylpiperazine-2,5-dione.Besides that, the thesis also reviewed new compounds of xanthone derivatives isolated from natural organism resources. 147 compounds are cited, among which 84 compounds were reported with biological activities. 14 new compounds come from marine-derived fungi, of which 12 have excellent pharmacology activities.