31 resultados para Crude extracts


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Soil microcosms contaminated with crude oil with or without chromium and copper were monitored over a period of 90 days for microbial respiration, biomass, and for dehydrogenase, lipase, acid phosphatase, and arylsulfatase activities. In addition, the community structure was followed by enumerating the total heterotrophic and oil-degrading viable bacteria and by performing a denaturing gradient gel electrophoresis (DGGE) of the PCR amplified 16S rDNA. A significant difference was observed for biochemical activities and microbial community structures between the microcosms comprised of uncontaminated soil, soil contaminated with crude oil and soil contaminated with crude oil and heavy metals. The easily measured soil enzyme activities correlated well with microbial population levels, community structures and rates of respiration (CO2 production). The estimation of microbial responses to soil contamination provides a more thorough understanding of the microbial community function in contaminated soil, in situations where technical and financial resources are limited and may be useful in addressing bioremediation treatability and effectiveness. (C) 2012 Published by Elsevier Ltd.

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The present study deals with the determination of the activation energy for the thermal decomposition of two renewable fuels crude glycerin and beef tallow. The activation energies were investigated by using a thermogravimetric analyzer (TGA) in the temperature range of 25-600 degrees C in atmosphere of synthetic air. The TG curves of the thermal decomposition process of both samples were divided into several phases and the second, called PH2, was chosen for the kinetic study because it is associated with the combustion ignition. Differential Thermal Analysis (DTA) showed an endothermic event at the PH2 region for the crude glycerin corresponding to devolatilization, while for beef tallow, this step presented an exothermic event, called LTO (low-temperature oxidation), which is correlated with devolatilization followed by combustion. For the entire PH2, activation energy values for crude glycerin were between 90 kJ mol(-1) and 42 kJ mol(-1), while for the beef tallow they ranged from 50 kJ mol(-1) to 113 kJ mol (1). The activation energy values obtained at the pre-ignition stage - conversion between 0 and 0.45 - showed that the crude glycerin with higher values requires an additional energetic support at the start of combustion processes and the beef tallow ignites more easily, presenting lower values. According to the Wolfer's equation, a direct relation between the activation energy and the ignition delay is established and the results of this study provides useful data for the development and design of new combustion chambers and engines when non-traditional fuels are used as feedstock. (C) 2012 Elsevier Ltd. All rights reserved.

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Solanum lycocarpum (Solanaceae) is native to the Brazilian Cerrado. Fruits of this species contain the glycoalkaloids solasonine (SN) and solamargine (SM), which display antiparasitic and anticancer properties. A method has been developed for the extraction and HPLC-UV analysis of the SN and SM in different parts of S. lycocarpum, mainly comprising ripe and unripe fruits, leaf, and stem. This analytical method was validated and gave good detection response with linearity over a dynamic range of 0.77-1000.00 mu g mL(-1) and recovery in the range of 80.92-91.71%, allowing a reliable quantitation of the target compounds. Unripe fruits displayed higher concentrations of glycoalkaloids (1.04% +/- 0.01 of SN and 0.69% +/- 0.00 of SM) than the ripe fruits (0.83% +/- 0.02 of SN and 0.60% +/- 0.01 of SM). Quantitation of glycoalkaloids in the alkaloidic extract gave 45.09% +/- 1.14 of SN and 44.37% +/- 0.60 of SM, respectively.

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The aim of this study was to examine the effects of Dorstenia asaroides extracts on cariogenic properties of the most cariogenic bacteria, Streptococcus mutans. Hexane (HFr), ethyl-acetate (EFr) and chloroform (CFr) extracts obtained from D. asaroides rhizomes were submitted to chemical analyses, Minimal Inhibitory Concentrations (MIC), glycolysis assay and S. mutans 12-h-old initial biofilms. Chemical characterization showed that all the extracts present furanocoumarins. The MIC values were 80 (HFr and CFr) and 50 mu g/mL (EFr). Acid production by S. mutans cells was significantly disrupted by HFr (12.5 mg/mL), EFr (at 2.5; 6.25 and 12.5 mg/mL) and CFr (at 2.5, 6.25 and 12.5 mg/mL) (p < 0.01). Topical applications of HFr, EFr and CFr significantly reduced the colony forming units of S. mutans biofilms compared with those treated with control group in order to 20,30 and 25% respectively (p < 0.01). The results of the present study suggest that rhizomes of D. asaroides had inhibitory effects on cariogenic properties of S. mutans. (C) 2012 Elsevier Ltd. All rights reserved.

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Styrax camporum Pohl, known in Brazil as estoraque do campo or cuia de brejo, has been used in the treatment of gastrointestinal diseases. The therapeutic action of S. camporum has been attributed to the ethyl acetate fraction, although the chemical composition of this fraction has not yet been analyzed. In this study, a high-performance liquid chromatography photodiode array detection (HPLC-PAD) method for analysis of Brazilian Styrax species has been developed. The compounds egonol (1) and homoegonol (2) were found to be present in all the samples investigated by HPLC. These compounds were isolated by open column chromatography followed by preparative TLC, and were identified by 1H NMR. Compounds 1 and 2 were thus proposed as phytochemical markers for Styrax, owing to their biological properties and presence in other Styrax species. The developed method has been validated and successfully applied for quantification of 1 and 2 in S. camporum dried leaves and crude ethanolic extracts from S. ferrugineus and S. pohlii aerial parts. Copyright (c) 2011 John Wiley & Sons, Ltd.

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The microencapsulation of Lippia sidoides extracts in blends of carbohydrates was investigated. The extraction conditions were determined through a 2(2) factorial design. The effects of the plant:solvent ratio (A - 7.5:100 and 15:100 m/m) and the extraction time (B - 30 and 90 min) on thymol content of extractive solutions were evaluated, using a 2:1 (v/v) of ethanol:water at a temperature of 50 degrees C, as a solvent system. The selected extract was subjected to spray drying. Blends of maltodextrin and gum arabic at different proportions (4:1; 3:2; 2:3; 0:1) (m/m) were used as encapsulating material. The protective effects of the maltodextrin and gum arabic blends were evaluated by determination of the thymol retention in the dried product, which ranged from 70.2 to 84.2% (related to the content in the extractive solution). An increase in the gum arabic to maltodextrin (DE10) ratio has positive effect on thymol retention. L. sidoides extracts and spray-dried products showed antifungal activity against tested fungal strains (Candida albicans - ATCC 64548, Candida glabrata - ATCC 90030, Candida krusei - ATCC 6258, and Candida parapsilosis - ATCC 22019), evidencing their potential as a natural antifungal agent for medicinal, food, and cosmeceutical purposes. (C) 2012 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

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Arrabidaea chica (crajiru) is an important Amazonian plant. Its extracts are used as red pigments, antimicrobial agents and astringents. Three different varieties of this species are cultivated in the Amazon region. In this work, direct infusions of A. chica extracts from these three varieties were analyzed via electrospray ionization mass spectrometry (ESI(+)-MS) fingerprinting. Derived data from the spectra were classified by using a multivariate method (PLS-DA, partial least squares-discriminant analysis). The direct method that is herein presented relies on extraction of dry, powdered leaves with acidified methanol/water solution with no further sample preparation. The resulting supernatants were analyzed by direct infusion ESI(+)-MS, which provides characteristic fingerprints of the sample composition. 3-Deoxyanthocyanidins are important substances in A. chica, their ions were used as markers in the PLS-DA data treatment. PLS-DA was able to differentiate the three varieties. ESI(+)-MS fingerprinting works as a simple and fast method to differentiate varieties of A. chica.

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Alicyclobacillus acidoterrestris is a spoilage-causing bacterium in fruit juices. The inactivation of this bacterium by commercial saponin and saponin purified extract from Sapindus saponaria fruits combined with heat-treatment is described. We investigated heat treatment (87, 90, 95, and 99 degrees C) with incubation time ranging from 0 to 50 min, in both concentrated and reconstituted juice. juices were inoculated with 1.0 x 10(4) CFU/mL of A. acidoterrestris spores for the evaluation of the best temperature for inactivation. For the temperatures of 87, 90, and 95 degrees C counts of cell viability decreased rapidly within the first 10 to 20 min of incubation in both concentrated and reconstituted juices; inactivation at 99 degrees C ensued within 1 and 2 min. Combination of commercial saponin (100 mg/L) with a very short incubation time (1 min) at 99 degrees C showed a reduction of 234 log cycle for concentrated juice A. acidoterrestris spores (1.0 x 10(4) CFU/mL) in the first 24 h of incubation after treatments. The most efficient treatment was reached with 300, 400 or 500 mg/L of purified extract of saponins from S. saponaria after 5 days of incubation in concentrated juice, and after 5 days with 300 and 400 mg/L or 72 h with 500 mg/L in reconstituted juice. Commercial saponin and purified extracts from S. saponaria had similar inactivation power on A. acidoterrestris spores, without significant differences (P>0.05). Therefore, purified extract of saponins can be an alternative for the control of A acidoterrestris in fruit juices. (C) 2012 Elsevier B.V. All rights reserved.

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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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The designation of biodiesel as an environmental-friendly alternative to diesel oil has improved its commercialization and use. However, most biodiesel environmental safety studies refer to air pollution and so far there have been very few literature data about its impacts upon other biotic systems, e.g. water, and exposed organisms. Spill simulations in water were carried out with neat diesel and biodiesel and their blends aiming at assessing their genotoxic potentials should there be contaminations of water systems. The water soluble fractions (WSF) from the spill simulations were submitted to solid phase extraction with C-18 cartridge and the extracts obtained were evaluated carrying out genotoxic and mutagenic bioassays [the Salmonella assay and the in vitro MicroFlow (R) kit (Litron) assay]. Mutagenic and genotoxic effects were observed, respectively, in the Salmonella/microsome preincubation assay and the in vitro MN test carried out with the biodiesel WSF. This interesting result may be related to the presence of pollutants in biodiesel derived from the raw material source used in its production chain. The data showed that care while using biodiesel should be taken to avoid harmful effects on living organisms in cases of water pollution. (C) 2011 Elsevier Ltd. All rights reserved.

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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.