Study On The Secondary Metabolites Of Two Marine-derived Fungus

Marine microorganisms is one of the main source of marine natural products, more than one-third of the new marine natural products derived from marine microorganisms,which at the same time is one of the real source of the modern marine medicine,even the actual biological sources of a dozen listed and clinical researchmarine drugsare the marine microorganisms. Endophytic fungi is a kind of special habitat of the microorganisms,generally refers to the one did not cause obvious symptoms of disease within the host organization during a certain period of time in the life cycle. Abundant microbes exist in soft corals, the mutual symbiotic microbes is the main producers of active natural products from soft corals symbionts.To discover new structure,active significant pharmaceutical molecules is the international research frontiers andhot spots.In China, there is no research reports on symbiotic fungus and their metabolites of soft coral Sinularia sp.. Our study group collected a number of samples of the soft coral Sinularia sp. from the coral reef sea near Hainan island of Sanya in the summer of 2012. The second chapter is the study of marine fungi isolated from the m, there is no report about the metabolites from S. boydii. Using normal phase silic a gel column chromatography, Sephadex LH-20 gel column chromatography, preparat ive HPLC and recrystallization for separation and purification, we collected compoun ds from the ethyl acetate phase of S. boydii. fermentation and the methanol phase o f their mycelium. The structures of 37 compounds were determined by comprehensiv e analysis of nuclear magnetic resonance spectroscopy, mass spectrometry, infrared s pectrometer, optical rotation, X-ray diffraction, circular dichroismand ECD combinedwith literature retrieval methods as follow:pseuboydone A(2-1a), pseuboydone B(2-1b), pseuboydone C(2-2), cyclo-(2, 2′-dimethylthio-Phe-Phe)(2-3), cyclo-(Phe-Phe)(2-4), phomazine B(2-5), bisdethiobis(methylthio) gliotoxin(2-6), boydine A(2-7),boydine B(2-8), ditryptophenaline(2-9), β-aflatrem(2-10), pseuboydone C(2-11), c yclopiamide E(2-12), speradine C(2-13), pseuboydone D(2-14), monohydroxyisoafl avinine(2-15), monohydroxyaflavinine(2-16), pseudofischerine(2-17), pyripyropene A(2-18), O-methylsterigmatocystin(2-19), 4-(1-hydroxy-1-methylpropyl)-2-isobutylpyr azin-2(1H)-one(2-20), 4-(1-hydroxy-1-methylpropyl)-2-secbutylpyrazin-2(1H)-one(2-21), asperfuran(2-22), 2-hydroxy-3,5-dimethyl-6-(1-methyl-1-propenyl)-4H-Pyran-4-one(2-23), 4-hydroxy-3-methyl-6-(1-methyl-1-propenyl)-2H-Pyran-2-one(2-24), phomaligol A(2-25), diorcinol(2-26),octalactin C(2-27), 5-tetradecyloxolan-2-one(γ-Octadecalac tone)(2-28), indole-3-carboxylic acid(2-29), indole-3-acetic acid(2-30), methyl-2-(1H-indol-3-yl)acetate(2-31), Indole-3-carbaldehyde(2-32), tryptophol(2-33), Nb-acetylt ryptamine(2-34), N-(2-hydroxyphenyl)-acetamide(2-35), N-(2-hydroxy-4-methylphenyl)-acetamide(2-36)。The compound 2-23 is obtained from natural products for the firs t time, the pseuboydone A(2-1a), pseuboydone B(2-1b), pseuboydone C(2-2), pse uboydone D(2-14)are new compounds, The absolute configuration of pseuboydone A(2-1a) was determined by X ray diffraction, the rest of three compounds were de termined by circular dichroism. The compounds of 2-1a,2-4,2-10,2-11,2-12,2-15~2-18 in vitro cytotoxicity test showed that compounds 2-1a,2-4,2-11,2-15,2-16 have significantly inhibition against Sf9 cells of the insect S. frugiperda., the inh ibition rateswere 91.50%, 92.38%, 90.43%, 97.04%, 97.51% respectively(rotenone u sed as a positive control). The biosynthetic pathway of the paspalinine, aflavinine, C PA, diketopiperazines,terpenoids and pyrazine ketoneswere proposed.In the third chapter, with soft coral Lobophytum sp. symbiotic fungus Trichoder ma asperellum as the research object, the fungal strain was cultured in Glucose-Pept one-Yeast extract(GPY) media in static for 60 days, the mycelium of which grew r apidly, is green and yellow. From the ethyl acetate phase of fermentation brothof Tr ichoderma asperellum., 13 compounds were obtained and identified as follow:rhodolamprometrin(3-1),melanoxazal(3-2),1-(2-furanyl)-1-penten-3-ol(3-3),4-acetyl-3-hy droxy-6-methyl-pyran-2-one(3-4),4-acetyl-3-hydroxy-6-methyl-pyran-2-one(3-5),N-a cetyltyramine(3-6), 4-hydroxy-N-(2-oxoethyl)-benzamide(3-7), cyclo(Phe-Ala)(3-8),c yclo(Tyr-Phe)(3-9), cyclo(Val-Phe)(3-10), cyclo(Val-Leu)(3-11),cyclo(Leu-Phe)(3-12),6(7)-cyclo-(pipecolinyl-Ala)(3-13)。Overall, metabolites from marine fungal strains were studied in this thesis, 50 compounds were isolated, covering chemical structure types from sesquiterpenes, indole alkaloids, meroterpenoids, pyrone cyclic peptides to lactones, reflecting the chemical diversity of metabolic products from marine symbiotic fungal as well as the huge biosynthetic potential of marine fungi.