RESUMO
Chemical investigation of the EtOAc extract of the endophytic fungus Bionectria ochroleuca, isolated from the inner leaf tissues of the plant Sonneratia caseolaris (Sonneratiaceae) from Hainan island (China), yielded two new peptides, pullularins E and F (1 and 2) together with three known compounds (3-5). The structures of the new compounds were unambiguously determined on the basis of one- and two-dimensional NMR spectroscopy as well as by high-resolution mass spectrometry. The absolute configurations of amino acids were determined by HPLC analysis of acid hydrolysates using Marfey's method. The isolated compounds exhibited pronounced to moderate cytotoxic activity against the mouse lymphoma cells (L5178Y) with EC50 values ranging between 0.1 and 6.7 µg/mL.
Assuntos
Embriófitas/microbiologia , Proteínas Fúngicas/química , Proteínas Fúngicas/isolamento & purificação , Hypocreales/química , Peptídeos/química , Peptídeos/isolamento & purificação , Folhas de Planta/microbiologia , Animais , Linhagem Celular Tumoral , China , Cromatografia Líquida de Alta Pressão/métodos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Proteínas Fúngicas/farmacologia , Hypocreales/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos , Camundongos , Peptídeos/farmacologiaRESUMO
Marine-derived fungi have been shown in recent years to produce a plethora of new bioactive secondary metabolites, some of them featuring new carbon frameworks hitherto unprecedented in nature. These compounds are of interest as new lead structures for medicine as well as for plant protection. The aim of this protocol is to give a detailed description of methods useful for the isolation and cultivation of fungi associated with various marine organisms (sponges, algae and mangrove plants) for the extraction, characterization and structure elucidation of biologically active secondary metabolites produced by these marine-derived endophytic fungi, and for the preliminary evaluation of their pharmacological properties based on rapid 'in house' screening systems. Some results exemplifying the positive outcomes of the protocol are given at the end. From sampling in marine environment to completion of the structure elucidation and bioactivity screening, a period of at least 3 months has to be scheduled.
Assuntos
Fungos/isolamento & purificação , Fungos/metabolismo , Micologia/métodos , Alternaria/isolamento & purificação , Alternaria/metabolismo , Animais , Antraquinonas/isolamento & purificação , Eucariotos/microbiologia , Fungos/classificação , Fungos/genética , Biologia Marinha/métodos , Poríferos/microbiologia , Rhizophoraceae/microbiologiaRESUMO
Two new 10-oxo-10H-phenaleno[1,2,3-de]chromene-2-carboxylic acids, xanalteric acids I (1) and II (2), and 11 known secondary metabolites were obtained from extracts of the endophytic fungus Alternaria sp., isolated from the mangrove plant Sonneratia alba collected in China. The metabolites were confirmed to be of fungal origin, and the structures of the new natural products were unambiguously elucidated on the basis of extensive one- and two-dimensional NMR spectroscopic studies and mass spectrometric analysis. The two new compounds 1 and 2 exhibited weak antibiotic activity against multidrug-resistant Staphylococcus aureus. Altenusin (3) displayed broad antimicrobial activity against several additional multidrug-resistant bacterial and fungal strains.
Assuntos
Alternaria/química , Antibacterianos/isolamento & purificação , Benzopiranos/química , Benzopiranos/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Myrtaceae/microbiologia , Antibacterianos/química , Antibacterianos/farmacologia , Aspergillus/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Benzopiranos/farmacologia , Candida albicans/efeitos dos fármacos , China , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , EstereoisomerismoRESUMO
Chemical examination of the endophytic fungus Pestalotiopsis sp., isolated from the leaves of the Chinese mangrove Rhizophora mucronata, yielded 11 new compounds including cytosporones J-N (1-3, 5-6), five new coumarins pestalasins A-E (8-12), and a new alkaloid named pestalotiopsoid A (14), along with the known compounds cytosporone C (4), dothiorelone B (7), and 3-hydroxymethyl-6,8-dimethoxycoumarin (13). The structures of the new compounds were unambiguously elucidated on the basis of extensive spectroscopic data analysis.
Assuntos
Alcaloides/isolamento & purificação , Ascomicetos/química , Cumarínicos/isolamento & purificação , Rhizophoraceae/microbiologia , Animais , Linhagem Celular , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria UltravioletaRESUMO
Six new chromones, named pestalotiopsones A-F (1-6), and the known derivative 7-hydroxy-2-(2-hydroxypropyl)-5-methylchromone (7) were obtained from the mycelia and culture filtrate of the mangrove endophytic fungus Pestalotiopsis sp., which was isolated from leaves of the Chinese Mangrove plant Rhizophora mucronata. Their structures were elucidated on the basis of spectroscopic data. Pestalotiopsones A-F are chromones having both an alkyl side chain substituted at C-2 and a free or substituted carboxyl group at C-5. Compound 6 exhibited moderate cytotoxicity against the murine cancer cell line L5178Y, whereas the other investigated compounds proved to be inactive.
