| Our research group had carried out the antimicrobial and antitumor active screening of the endophytic fungi,two strains YE3048 and YE3069 showed potent bioactivities.In this thesis,the chemical constituents of the fermentation products from two strains were studied.The strain YE3069 was identified as Aspergillus terreus using its ITS sequence and morphologic characteristics.The strain YE3408 was determined to be Chaetomium globosum in our previous study.The chemical constituents of the fermentation extracts were isolated by column chromatography on silica gel,RP-18 and Sephadex LH-20.The spectroscopic methods,including 1D and 2D NMR,MS were used to determine the structures of the compounds.A total of 36 compounds were isolated and identified from the two strains.There are eight new compounds and three new natural products.Twenty-seven compounds were obtained and identified from the broth of the strain YE3069,in which there are seven new compounds(1-7).They were identified as 6-((3E,5E)-5,7-dimethyl-2-oxonona-3,5-dien-1-yl)-2,4-dihydroxy-3-methylbenzoic acid(1),(5S,6R)-5,6-dihydroxy-1-((S,E)-4-hydroxy-4-((2R,3R)-3-methyltetrahydrofuran-2-yl)pent-2-enoyl)-5-methyl-6,7-dihydroisobenzofuran-4(5H)-one(2),2,4-dihydroxy-3-methyl-6-((2E,4E)-5-((2R,3R)-3-methyltetrahydrofuran-2-yl)hexa-2,4-dien-1-yl)benzald ehyde(3),5-(1-hydroxypropan-2-yl)-4-methoxy-5,6-dihydro-2H-pyran-2-one(4),9-demethoxy-nosporin A(5),(2R,2'S,3R,3S)-3-hydroxy-2,3'-dimethylhexahydro-[2,2'-bifuran]-5(2H)-one(6),5-(sec-butyl)-4-methylfuran-2(5H)-one(7).Compounds 11,12 and 26 are new natural products and named as 3-methoxy-trans-4-hydroxy-5-methyl-2-cyclopentenone(11)?4-hydroxy-2,3-dimethyl-2-cyclopenten-1-one(12)and 2-hydroxy-5-methylcyclopentanemethanol(26).The other known compounds were identified as acetylaszonalenin(8),(E)-3-methoxy-3-(5-methoxy-4-methyltetrahydro furan-3-yl)acrylic acid(9),(E)-4-(prop-1-en-1-yl)cyclopentane-1,2-diol(10),butyrolactone I(13),aspernolide A(14),terretonin(15),questin(16),emodin(17),4-hydroxykigelin(18),7-hydroxy-3,5-dimethyl-isochromen-l-one(19),6-methoxy mellein(20),vomifoliol(21),4,6-dimethyl-2,4-octadienoic acid(22),2-cyclopenten-1-one(23),4-hydroxymethyl-3-methoxy-5-methylcyclopent-2-enone(24),terrein(25)and 4-hydroxybenzaldehyde(27).Compounds 23 and 24 were isolated from Aspergillus terreus for the first time.The results showed that the secondary metabolites of Aspergillus terreus YE3069 were rich in chemical structure,including azaphilone polyketides,sestercterpenes,butyrolactones,anthraquinones,isocoumarin,alkaloid,furane derivatives,cyclopentanone derivatives and other types.Nine compounds were obtained from the fermentation extract of the strain YE3048,including one new chaetoglobosin,named as penochalasin K(28).The other eight known compounds are armochaetoglobin ?(29),chaetoglobosin A(30),chaetoglobosin C(31),chaetoglobosin U(32),prochaetoglobosin ?(33),prochaetoglobosin ?(34),uracil(35)and urdine(36).Chaetoglobosin is the major type of secondary metabolites of the strain YE3048.Antimicrobial activity test showed that compounds 13 and 14 had a certain inhibitory effect on Bacillus subtilis,with a minimum inhibitory concentration(MIC)of 64 ?g/mL.Compound 13 had a significant activity against Salmonella typhimurium,with a MIC value of 32 ?g/mL.Compounds 30 and 34 had significant inhibitory activity against Bacillus subtilis,with MIC values of 32 and 16 ?g/mL.Compound 33 had certain inhibitory activity against Salmonella typhimurium,with the MIC value of 64 ?g/mL. |
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