During our studies concerning endophytic fungi, two indole alkaloids were co-produced with verruculogen by Penicillium brasilianum isolated from Melia azedarach (Meliaceae). The compounds were isolated by the use of combined chromatographic procedures and identified by physical methods, mainly 1D- and 2D-NMR experiments. This article also describes the production of verruculogen TR-2, first described for this species of Penicillium, and a verruculogen TR-2C-11 epimer, that is a novel fungal natural product.
View Article and Find Full Text PDFThe oxidative potential of the fungus Penicillium brasilianum, a strain isolated as an endophyte from a Meliaceae plant (Melia azedarach), was investigated using 1-indanone as a substrate to track the production of monooxygenases. The fungus produced the dihydrocoumarin from 1-indanone with the classical Baeyer-Villiger reaction regiochemistry, and (-)-(R)-3-hydroxy-1-indanone with 78% ee. Minor compounds resulting from lipase and SAM activities were also detected.
View Article and Find Full Text PDFIn our continuous studies on the chemistry of the endophytic fungus Penicillium griseoroseum, an endophyte isolated from fruits of Coffea arabica, we isolated clavatol, a dimethylated tetraketide, and its dimer which appears to be a novel natural compound. The studies also resulted in the identification of two known tetronic acids, viridicatic acid and terrestric acid, found in ethyl acetate and n-butanol extracts. Spectroscopic studies using 1-D and 2-D NMR and MS/MS analysis were performed to determine the structures of these compounds, first reported by this Penicillium.
View Article and Find Full Text PDFJ Microbiol Biotechnol
July 2011
Endophytic fungi, isolated from a number of different species of tropical plants, were investigated for lipid biodiesel precursor production. The extracts produced from liquid cultures of these fungi were subjected to acidcatalyzed transesterification reactions with methanol producing methyl esters and then analyzed through chromatographic (GC-FID) and spectrometric techniques (MS, NMR ¹H). The European Standard Method, EN 14103, was used for the quantification of methyl esters extracted from the fungi of the species and genera studied.
View Article and Find Full Text PDFBiosynthetic studies on brasiliamides, potently convulsive and bacteriostatic compounds from an endophytic Penicillium brasilianum isolated from Melia azedarach (Meliaceae), confirms their phenylpropanoid origin, which is very uncommon in fungi. Feeding experiments with [2-(13)C]- phenylalanine indicated the incorporation of two units of this amino acid on brasiliamide structures. The first step in the phenylpropanoid pathway to those compounds was evaluated through enzymatic bioassays and confirmed the phenylalanine ammonia-lyase (PAL) participation.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
February 2009
The title meroterpene neoaustin {systematic name: (1'S,2'R,3S,7'R,9'S,11'S,12'R)-11'-hydr-oxy-2,2,2',9',12'-penta-methyl-6',15'-dimethyl-ene-2,6-dihydro-13'-oxaspiro-[pyran-3,5'-tetra-cyclo-[7.5.1.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
January 2009
THE TITLE MEROTERPENE PREAUSTINOID A (SYSTEMATIC NAME: methyl 15-hydr-oxy-2,6,6,10,13,15-hexa-methyl-17-methyl-ene-7,14,16-trioxotetra-cyclo-[11.3.1.
View Article and Find Full Text PDFThe mosquito Aedes aegypti is an increasing problem of public health, being the vector responsible for dengue and Yellow Fever in tropical and subtropical regions. The aim of this work was to determine the potential larvicidal activity of a series of meroterpenoids, compounds 1-7, previously obtained fungal secondary metabolites from Penicillium sp., against the third-instar larvae of A.
View Article and Find Full Text PDFComplete assignments of 1H and 13C NMR chemical shifts of the polyketides aurasperone A and fonsecinone A were made by means of nuclear Overhauser enhancement and heteronuclear NMR correlation experiments. These compounds were isolated for the first time from Aspergillus aculeatus, an endophytic fungus obtained from leaves of Melia azedarach(Meliaceae).
View Article and Find Full Text PDFThe stems of Khaya anthotheca yielded two new limonoids, which were identified on the basis of spectroscopic analysis as 1alpha,8alpha-oxido-3beta-acetoxy-2alpha-acylperoxy-1alpha,14alpha-dihydroxy-[3.3.1(10,2)]-bicyclomeliac-7,19-olide (3) and 3-acetoxy-8,14-dien-8,30-seco-khayalactone (4).
View Article and Find Full Text PDFZ Naturforsch C J Biosci
January 2004
From the methanol extract of Penicillium sp. cultivated on sterilized rice for three weeks we isolated three new meroterpenes preaustinoid A1, A2 and B1. The fungus was isolated from the root bark of Melia azedarach after surface sterilization.
View Article and Find Full Text PDFA Pestalotiopis sp. was isolated from the trunk bark of Pinus taeda. The fungus was cultivated in liquid medium and produced three highly oxygenated caryophyllene sequiterpene derivatives, named pestalotiopsolide A, taedolidol and 6-epitaedolidol, respectively.
View Article and Find Full Text PDFThe dichloromethane extract from leaves of Dictyoloma vandellianum afforded five alkaloids 2-(14'-hydroxy-14',15'-dimethylhexadecanyl)-4-quinolone, 2-(12'-hydroxy-12'-methyltridecanyl)-3-methoxy-4-quinolone, 2-(12'-hydroxy-12'-methyltridecanyl)-4-quinolone, 2-(14'-hydroxy-14',15'-dimethylhexadecanyl)-3-methoxy-4-quinolone, 6-methoxydictyolomide A, besides the known alkaloid 8-methoxyflindersine and beta-sitosterol. The presence of 2-alkyl-4(1H)-quinolones in D. vandellianum shows strong similarities with the Zanthoxyleae, which contains several 2-alkyl-4-quinolones.
View Article and Find Full Text PDFPhytochemistry
December 2002
A Penicillium sp was isolated from the root bark of Melia azedarach and cultivated over sterilized rice. After chromatographic procedures, two meroterpenes, named preaustinoid A and B, were obtained in addition to the known alkaloid verruculogen. Their structures were identified by extensive spectroscopic studies, and they exhibited moderate bacteriostatic effects on Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus sp.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
October 2002
Careful analysis of the electron impact (EI) mass spectral data obtained for the trimethylsilyl (TMS) ethers of known trichothecene mycotoxins of the deoxynivalenol group permitted the construction of a database useful for the identification of these mycotoxins directly from a gas chromatography/mass spectrometry (GC/MS) run. Structures of the ions at m/z 103, 117, 147 and 191 were elucidated by high-resolution mass spectrometry (HRMS) and a fragmentation scheme was suggested. The relative abundances of these ions in the mass spectra of the trichothecenes allowed a fast structural diagnosis during analysis of biological matrices.
View Article and Find Full Text PDFThe ethyl acetate extract of roots of Tephrosia candida afforded three new spirorotenoids belonging to a new class of spirocompounds, named tephrospirolactone, tephrospiroketone I, and tephrospiroketone II. The structures of these compounds were determined mainly based on spectral analysis. The only known spirorotenoid described in the literature is amorphispironone, isolated from Amorpha fruticosa.
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