RESUMO
The chemical reactions carried out by microorganisms have been used as a tool in modern chemistry. This paper reports the production of mycophenolic acid and a new phthalide by the endophytic fungus Penicillium crustosum obtained from coffee seeds. The fungus was cultivated in a liquid medium for a period of seven days and after that the culture medium was divided into four treatments: A, B, C and D, to which different organic substances were added. Treatment A was maintained as the control to evaluate the occurrence of biotransformation. Organic acids were added to the culture media of treatments B (ferulic and quinic acids) and C [cinnamic and 3,4-(methylenedioxy) cinnamic acids], and caffeine was added in the treatment D. All these organic compounds were dissolved in DMSO, and the fermentation was maintained for more 13 days, totalizing 20 days. Mycophenolic acid was isolated from the culture with no added acids (treatment A). Mycophenolic acid and a new phthalide, 5-hydroxy-7-methoxy-4-methylphthalide were isolated from treatments B and C, and mycophenolic acid and caffeine (added to the culture medium) were isolated from treatment D. The structures were determined by NMR techniques and confirmed by MS and MS/MS techniques.
Assuntos
Benzofuranos/metabolismo , Ácido Micofenólico/biossíntese , Penicillium/metabolismo , Benzofuranos/química , Biotransformação , Café/microbiologia , Meios de Cultura , Espectroscopia de Ressonância Magnética , Ácido Micofenólico/química , Espectrometria de Massas em Tandem , Fatores de TempoRESUMO
This present work describes the application of liquid chromatography-solid phase extraction-nuclear magnetic resonance spectroscopy to analyse Alternaria alternata crude extracts. Altenusin (1), alternariol (2), 3'-hydroxyalternariol monomethyl ether (3), and alternariol monomethyl ether (4), were separated and identified. High-resolution mass spectrometry confirmed the proposed structures. The cytotoxic effects of these compounds towards plants were determined using soybean (Glycine max) cell cultures as a model. EC(50) values which range from 0.11 (± 0.02) to 4.69 (± 0.47) µM showed the high cytotoxicity of these compounds.
Assuntos
Alternaria/química , Glycine max/efeitos dos fármacos , Micotoxinas/química , Técnicas de Cultura de Células , Extratos Celulares/química , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Micotoxinas/toxicidade , Ressonância Magnética Nuclear Biomolecular , Extração em Fase SólidaRESUMO
For over a century, Catuaba has been used in Brazilian folk medicine as an aphrodisiac even though the identity of the plant material employed is often uncertain. The species recommended by the Brazilian Pharmacopeia is Anemopaegma arvense (Bignoniaceae), but many other plants, regionally known as Catuaba, are commercialised. Frequently, the quality control of such a complex system is based on chemical markers that do not supply a general idea of the system. With the advent of the metabolomics approach, a global analysis of samples becomes possible. It appears that (1)H-NMR is the most useful method for such application, since it can be used as a wide-spectrum chemical analysis technique. Unfortunately, the generated spectra is complex so a possible approach is to look at the metabolite profile as a whole using multivariate methods, for example, by application of principal component analysis (PCA). In the present paper, we describe for the first time a proton high-resolution magic angle spinning nuclear magnetic resonance ((1)H-HR-MAS NMR) method coupled with PCA for the metabolomic analysis of some commercial Catuaba samples, which provided a reduction in the time required for such analysis. A comparative study of HPLC, HR-MAS and liquid-NMR techniques is also reported.
Assuntos
Bignoniaceae/química , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Meliaceae/química , Afrodisíacos/química , Bignoniaceae/classificação , Medicina Tradicional , Meliaceae/classificação , Análise Multivariada , Casca de Planta/química , Folhas de Planta/química , Raízes de Plantas/químicaRESUMO
Complete 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).
Assuntos
Aspergillus/química , Cromonas/química , Espectroscopia de Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/normas , Naftalenos/química , Pironas/química , Isótopos de Carbono , Cromonas/isolamento & purificação , Estrutura Molecular , Naftalenos/isolamento & purificação , Prótons , Pironas/isolamento & purificação , Padrões de ReferênciaRESUMO
A 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. The sesquiterpenes were isolated by silica gel based chromatographic procedures and their structures were elucidated by NMR spectroscopic data.