Study On The Chemical Constituents Of Three Coral-associated Fungi From Dongsha

Under the oppression of the abominable marine environment,marine microorganisms and marine organisms(such as corals,sponges,etc)have formed a complex symbiotic relationship.These marine microorganisms form their own way of metabolism during their symbiosis with their hosts,producing many new secondary metabolites with novel structure and remarkable activity.In recent years,the research of secondary metabolites of marine epiphytic microbes has become a hot spot in marine drug research.In this study,the chemical constituents of three co-epiphytic fungi Pseudallescheria boydii,Arthrinium sp.and Curvularia lunata.were studied through column chromatography on Sephadex LH-20,silica gel,ODS,preparative HPLC and so on.Analyzed by 1D-NMR&2D-NMR spectrum data and comparied with reported datal,the compounds were identified,including macrolides,terpenoids,steroids and so on.13 compounds were isolated from the ethyl acetate extract of the first corallic epiphytic fungusPseudallescheriaboydiifermentationbroth.Theyarenamedas(5S,6S,7R)-2,6,7-trimethyl-1,9-dimethylene-3-((2S,3S,Z)-3-methylhept-4-en-2-yl)-7-(1-phenylvinyl)spiro[4.4]non-2-ene(E-1),2-((1S*,4S*,5S*)-4-hydroxy-4-(hydroxymethyl)bicyclo[3.1.0]hexan-1-yl)-6-methylhept-5-ene-1,2-diol(E-3),(3S,5S,8S,10R,13R,17R)-10,13-dimethyl-17-((R,E)-6-methylhept-3-en-2-yl)-1,3,4,10,12,13,14,15,16,17-decahydro-2H-5,8-epidioxycyclopenta[a]phenanthren-3-ol(E-8),(3S,5S,8S,10R,13R,17R)-10,13-dimethyl-17-((R,E)-6-methylhept-3-en-2-yl)-1,3,4,9,10,11,12,13,14,15,16,17-dodecahydro-2H-5,8-epidioxycyclopenta[a]phenanthren-3-ol(E-9),(3S,4aR,5aR,9R,9aR,11bR)-9-((2R5R,E)-5,6-dimethylhept-3-en-2-yl)-3-hydroxy-9a,11b-dimethyltetradecahydrocyclopenta[1,2]phenant hro[8a,9-b]oxiren-6(5aH)-one(E-10),(2S,3S,4R,4aR,5R,6R,8aR)-4,4a,6,8a-tetrahydroxy-5-methoxy-2,4-dimethyl-3-(3-methylbut-2-en-1-yl)decahydro-2λ~3-isothiochromene-2-oxid e(E-11),(2S,3S,4R,4aR,5S,8aR)-4,4a,8a-trihydroxy-5-methoxy-2,4-dimethyl-3-(3-methylbut-2-en-1-yl)octahydro-2l3-isothiochromen-6(2H)-one-2-oxide(E-12),(10R,13R)-17-((2R,5R,E)-5,6-dimethylhept-3-en-2-yl)-10,13-dimethyl-1,2,9,10,11,12,13,15,16,17-dec ahydro-3H-cyclopenta[a]phenanthren-3-one(E-22),(5R,6R)-5-(chloromethyl)-5-hydroxy-6-(hydroxymethyl)-6-((2S,3R)-2-methyl-3-(3-methylbut-2-en-1-yl)oxiran-2-yl)tetrahydro-2H-pyran-2-one(E-27),N-((4S,5R,7S,9S)-7-ethyl-9-hydroxy-8,8-dimethyl-2-oxo-1,6-dioxaspiro[4.5]decan-4-yl)acetamide(E-40),(1R)-4-methyl-1-(6-methyl-2-methylenebicyclo[3.1.1]heptan-6-yl)pent-3-en-1-ol(E-29),(3S,4R,4aR,5S,8aR)-4,4a,8a-trihydroxy-5-methoxy-4-methyl-3-(3-methylbut-2-en-1-yl)octahydro-6H-isothiochromen-6-one(E-51),(2S,3R,4R)-4-(chloromethyl)-3,4-dihydroxy-2-methoxy-3-((2S,3R)-2-methyl-3-(3-methylbut-2-en-1-yl)oxiran-2-yl)cyclohexan-1-one(E-63).These compounds include terpenoidsandsteroids.Theterpenoidscontainmultiplesubstitutions,like halogen-substituted,sulfur-substituted,and sulfonyl-substituted,fully illustrating the complexity and uniqueness of microbial metabolic pathways.The two six six-membered rings in compounds E-11,E-12 and E-53 are all trans-fused.6 compounds were isolated from the ethyl acetate extract of the second soft corals co epiphytic fungi Arthrinium sp.fermentationbroth.We call them as 5-hydroxy-3-isopropyl-4-methoxyfuranone(B-1),(S)-11,13-dihydroxy-4-methyl-4,5,6,7,8,9-hexahydro-2H-benzo[d][1]oxacyclododecine-2,10(1H)-dione(B-2),24-Methylcholesta-7,22-diene-3β,5ɑ,6β-triol(B-3),3β-hydroxy-5,9-epoxy-(22E,24R)-ergosta-7,22-dien-6-one(B-5),(S)-3,4-Dihydro-8-hydroxy-3-methylisochromen-1-one(B-12),3a,7-dihydroxy-6,6,9a-trimethyldecahydronaphtho[1,2-c]furan-3(1H)-one(B-21).These compounds are all known compounds including macrolides,steroids,steroids,polyketides,etc.5 compounds were isolated from the ethyl acetate extract of the third soft corals coepiphytic fungi Arthrinium sp.fermentation broth.They are named as(3S,5E,7S,8S,9S,11E)-7,8,9,14,16-pentahydroxy-3-methyl-3,4,7,8,9,10-hexahydro-1H-benzo[c][1]oxacyclot etradecin-1-one(C-1),(3S,5E,7S,8S,9S,11E)-7,8,9,16-tetrahydroxy-14-methoxy-3-methyl-3,4,7,8,9,10-hexahydro-1H-benzo[c][1]oxacyclotetradecin-1-one(C-2),(4bR,5aR,7S,8S,9S,13S,E)-1,3,7,8,9-pentahydroxy-13-methyl-4b,5a,6,7,8,9,12,13-octahydro-15H-benzo[c]oxireno[2,3-e][1]oxacyclotetradecin-15-one(C-3),(3aS,5aR,8aR)-6-((2R,5R,E)-5,6-dimethylhept-3-en-2-yl)-3a-hydroxy-5a-methyl-3a,4,5,5a,6,7,8,8a-octahydro-2H-indeno[5,4-b]furan-2-one(C-4),3-hydroxy-3-(2-oxopropyl)indolin-2-one(C-5).These compounds are also known compounds.The NMR data of the compound C-1 are reported in detail for the first time.