24 resultados para ether extracts


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Multivariate analyses of UV-Vis spectral data from cachaca wood extracts provide a simple and robust model to classify aged Brazilian cachacas according to the wood species used in the maturation barrels. The model is based on inspection of 93 extracts of oak and different Brazilian wood species by a non-aged cachaca used as an extraction solvent. Application of PCA (Principal Components Analysis) and HCA (Hierarchical Cluster Analysis) leads to identification of 6 clusters of cachaca wood extracts (amburana, amendoim, balsamo, castanheira, jatoba, and oak). LDA (Linear Discriminant Analysis) affords classification of 10 different wood species used in the cachaca extracts (amburana, amendoim, balsamo, cabreuva-parda, canela-sassafras, castanheira, jatoba, jequitiba-rosa, louro-canela, and oak) with an accuracy ranging from 80% (amendoim and castanheira) to 100% (balsamo and jequitiba-rosa). The methodology provides a low-cost alternative to methods based on liquid chromatography and mass spectrometry to classify cachacas aged in barrels that are composed of different wood species.

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Aqueous extracts from wood biotreated with the white-rot fungus Ceriporiopsis subvermispora were evaluated for their Fe3+- and Cu2+-reducing activities and their anti- or prooxidant properties in Fenton-like reactions to decolorize the recalcitrant dye Azure B. The decolorization of Azure B was strongly inhibited in the presence of 10% (v/v) wood extracts. Only 0.1% (v/v)-diluted extracts provided some enhancement of the Azure B decolorization. The iron-containing reactions decolorized more Azure B and consumed substantially more H2O2 than the reactions containing copper. This study demonstrates that water-soluble wood phenols exert anti- or prooxidant effects that depend on their concentration in the reactions and on the type of cation, Fe3+ or Cu2+, used to convert H2O2 to OH radicals. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.

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The aim of the study was to screen 11 selected traditional medicinal plants from West Africa for their in vitro antiplasmodial activity in order to determine the activity of single and of combination of plant extracts and to examine the activity of isolated pure compounds. Ethanolic and aqueous extracts of the 11 selected plants and pure compounds from Phyllanthus muellerianus and Anogeissus leiocarpus were tested in vitro against Plasmodium falciparum 3D7. Proliferation inhibitory effects were monitored after 48 h. Among the plants and pure compounds investigated in this study, geraniin from P. muellerianus, ellagic, gentisic, and gallic acids from A. leiocarpus, and extracts from A. leiocarpus, P. muellerianus and combination of A. leiocarpus with P. muellerianus affected the proliferation of P. falciparum most potently. Significant inhibitory activity was observed in combination of A. leiocarpus with P. muellerianus (IC50 = 10.8 mu g/ml), in combination of A. leiocarpus with Khaya senegalensis (IC50 = 12.5 mu g/ml), ellagic acid (IC50 = 2.88 mu M), and geraniin (IC50 = 11.74 mu M). In general growth inhibition was concentration-dependent revealing IC50 values ranging between 10.8 and -40.1 mu g/ml and 2.88 and 11.74 mu M for plant extracts and pure substances respectively. Comparison with literature sources of in vivo and in vitro toxicity data revealed that thresholds are up to two times higher than the determined IC50 values. Thus, the present study suggests that geraniin from P. muellerianus; ellagic acid, gallic acid, and gentisic acid from A. leiocarpus; and combination of extracts from A. leiocarpus with either P. muellerianus or K. senegalensis could be a potential option for malaria treatment.

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Molecular dynamics simulations have been performed for ionic liquids based on a ternary mixture of lithium and ammonium cations and a common anion, bis(trifluoromethylsulfonyl)imide, [Tf2N](-). We address structural changes resulting from adding Li+ in ionic liquids with increasing length of an ether-functionalized chain in the ammonium cation. The calculation of static structure factors reveals the lithium effect on charge ordering and intermediate range order in comparison with the neat ionic liquids. The charge ordering is modified in the lithium solution because the coordination of [Tf2N](-) toward Li+ is much stronger than ammonium cations. Intermediate range order is observed in neat ionic liquids based on ammonium cations with a long chain, but in the lithium solutions, there is also a nonhomogenous distribution of Li+ cations. The presence of Li+ enhances interactions between the ammonium cations due to correlations between the oxygen atom of the ether chain and the nitrogen atom of another ammonium cation.

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Smallanthus sonchifolius (Poepp.) H. Rob. , Asteraceae, known as yacon, is an herb that is traditionally used for the treatment of diabetes in folk medicine. However, recent studies have demonstrated that this plant has other interesting properties such as anti-microbial and anti-inflammatory actions. Thus, the purpose of this study was to evaluate the topical anti-inflammatory property of different extracts prepared from yacon leaves and analyze the role of different chemical classes in this activity. Three yacon leaf extracts were obtained: aqueous extract, where chlorogenic acid derivatives and sesquiterpene lactones were detected; leaf rinse extract, rich in sesquiterpene lactones; and polar extract, rich in chlorogenic acid derivatives. All the extracts exhibited anti-edematogenic activity in vivo (aqueous extract: 25.9% edema inhibition at 0.50 mg/ear; polar extract: 42.7% inhibition at 0.25 mg/ear; and leaf rinse extract: 44.1% inhibition at 0.25 mg/ear). The leaf rinse extract furnished the best results regarding neutrophil migration inhibition, and NO, TNF-? and PGE2 inhibition. These data indicate that both sesquiterpene lactones and chlorogenic acid derivatives contribute to the anti-inflammatory action, although sesquiterpene lactones seem to have more pronounced effects. In conclusion, yacon leaf extracts, particularly the sesquiterpene lactone-rich extract, has potential use as topical anti-inflammatory agent.

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Ethyl acetate extracts of cultures grown in liquid Czapek and on solid rice media of the fungal endophyte Fusarium oxysporum SS46 isolated from the medicinal plant Smallanthus sonchifolius (Poepp.) H. Rob., Asteraceae, exhibited considerable cytotoxic activity when tested in vitro against human cancer cells. Chromatographic separation yielded anhydrofusarubin (1) and beauvericin (2) that were identified based on their ¹H and 13C NMR data. Compounds 1 and 2 showed the strongest cytotoxic activity against different cancer cell lines. Compound 2 also showed promising activity against Leishmania braziliensis. Hexanic extract of F. oxysporum SS50 grown on solid rice media also afforded a mixture of compounds that displayed cytotoxic activity against different cancer cell lines. Chemical analysis of the mixture of compounds, investigated by gas chromatography-mass spectrometry (GC-MS), showed that there was a predominance of methyl esters of fatty acids and alkanes.

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The genus Eremanthus is recognized by the predominance of sesquiterpene lactones from the furanoheliangolide type, a class of substances extensively tested against cancer cell lines. Thus, the species E. crotonoides (DC.) Sch. Bip., Asteraceae, obtained on "restinga" vegetation was evaluated against U251 and U87-MG glioma cell lines using the MTT colorimetric assay. Dichloromethane fraction was cytotoxic to both glioblastoma multiforme cell lines. We then conducted UPLC-PDA-ESI-MS/MS analysis of the dichloromethane fraction, which allowed the identification of the sesquiterpene lactones centratherin and goyazensolide. The isolation of centratherin was performed using chromatographic techniques and the identification of this substance was confirmed according to NMR data. Cytotoxic activity of centratherin alone was also evaluated against both U251 and U87-MG cells, which showed IC50 values comparable with those obtained for the commercial anticancer drug doxorubicin. All the tested samples showed cytotoxic activity against glioblastoma multiforme cells which suggests that E. crotonoides extracts may be important sources of antiproliferative substances and that the centratherin may serve as prototype for developing new antiglioblastoma drugs.

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The aims of this study were to test (i) the effect of time of tissue and RNA extracts storage on ice and (ii) the effect of repeated freeze–thaw cycles on RNA integrity and gene expression of bovine reproductive tissues. Fragments of endometrium (ENDO), corpus luteum (CL) and ampulla (AMP) were subdivided and incubated for 0, 1, 3, 6, 12 or 24 h on ice. RNA extracts were incubated on ice for 0, 3, 12 or 24 h, or exposed to 1, 2, 4 or 6 freeze–thaw cycles. RNA integrity number (RIN) was estimated. Expression of progesterone receptor (PGR) and cyclophilin genes from RNA extracts stored on ice for 0 or 24 h, and 1 or 6 freeze–thaw cycles was measured by qPCR. Tissue and RNA extract incubation on ice, and repeated freeze–thaw cycles did not affect RIN values of RNA from ENDO, CL or AMP. Storage on ice or exposure to freeze–thaw cycles did not affect Cq values for PGR or cyclophilin genes. In conclusion, neither generalized RNA degradation nor specific RNA degradation was affected by storage of tissue or RNA extracts on ice for up to 24 h, or by up to 6 freeze–thaw cycles of RNA extracts obtained from bovine ENDO, CL and AMP.

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Triblock copolymers are made of monomer segments, being the central part usually hydrophobic and the outer parts hydrophilic. By varying sizes, molecular weights and monomer types of the segments one obtains different final molecules, with different physico-chemical properties, which are directly related to the performance of the final product. Looking for new products to be used, among other possibilities, in biological applications, a new polymer (Figure 1) was synthesized by the Dow Chemical and studied by Size Exclusion Chromatography, Fourier Transformed Infrared Spectrometry, Small-angle X-ray Scattering (SAXS) and its cloud point was determined by measuring light transmittance. The studies showed low molecular polydispersivety, but different polarities in the macromolecules fractions. Due to the low solubility of Diol in water, a mixture of water/butyl diglycol was used as solvent. An extensive analysis by SAXS was performed for concentrations from 50 wt% to 80 wt% of Diol in solution. Small concentrations showed very low signal to noise ratio, making it impossible to be analysed. The scattering intensity including the form factor of polydisperse non-homogeneous spheres, and the structure factor of interacting hard spheres was fitted to the curves. As the polymer concentration is high, the fitting of form factors of direct and reverse micelles were compared. The results for direct micelles were better up to 80 wt%, whereas at 90 wt% and 95 wt% the curves were better fitted by reverse micelles. It might seem odd that direct micelles are present up to such high concentrations, but it might have been caused by the presence of butyl diglycol, which increases the solubility of Diol in water. The inner and outer radius of the micelles, electron density distribution, and interaction radius of the micelles were obtained. The polydispersivety increases with Diol concentration. Besides, the interaction radius increases with solvent concentration, even when reversed micelles are present. In the last case, accompanied by an increase of inner radius (water content), as there are fewer Diol molecules to involve the water nuclei, which become larger, further apart, and in less number.