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Search Results: 1 - 10 of 175371 matches for " Alaíde Braga de; "
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Enzyme-linked immunosorbent assay (ELISA) immunoassaying versus microscopy: advantages and drawbacks for diagnosing giardiasis
Vidal, Alaíde Mader Braga;Catapani, Wilson Roberto;
Sao Paulo Medical Journal , 2005, DOI: 10.1590/S1516-31802005000600006
Abstract: context and objective: giardiasis is common in brazil. for laboratory diagnosis, the method most utilized is microscopic examination of fecal samples, but the immunoenzymatic method is also available. the aim of this work was to verify the advantages and drawbacks of immunoassaying versus microscopy for diagnosing giardia lamblia, when a single fecal sample is analyzed. design and setting: prospective, double-blind study at the parasitology laboratory of faculdade de medicina da funda??o abc. methods: samples were prepared according to the traditional sedimentation (hoffman, pons and janer) and faust methods. results were deemed positive when giardia lamblia was found by one or both methods. the prospect elisa kit was used for detecting giardia lamblia-specific antigen, in accordance with the manufacturer's instructions. results were expressed on a visual scale as negative or positive (+, ++, +++ or ++++). results: the elisa test was positive even when a significant proportion of corresponding samples examined by microscopy were negative. this trend was statistically significant (p < 0.001). the overall concordance of results between the elisa test and microscopic examination of single samples was only moderate (0.50 by kappa test). conclusion: the elisa test is useful when just searching for giardia lamblia, because of its high sensitivity. for daily practice, we recommend microscopy, which is much cheaper and can also detect other parasites. the low positivity of single samples in this method can be overcome by using three samples, as recommended by most authors.
Avalia??o quantitativa de cardenolídeos no cultivar experimental de Digitalis lanata do maci?o do itatiaia e perspectivas de seu emprego industrial
Braga, Fern?o Castro;Kreis, Wolfgang;Récio, Rubens Almeida;Oliveira, Alaíde Braga de;
Química Nova , 1997, DOI: 10.1590/S0100-40421997000500008
Abstract: the content of digoxin and lanatoside c (jointly quantified), lanatoside a, lanatoside b, glucoevatromonoside, odorobioside g, glucogitoroside, glucoverodoxine, glucodigifucoside and digitalinum verum was determined by hplc in digitalis lanata harvested in brazil, as well as in clones industrially employed for the production of cardenolides. the brazilian plants presented greater variation in the contents of cardenolides than the analyzed clones. lanatoside c and digoxin concentrations were higher in the clones (6120±640 nmol/g dry leaf) than in the brazilian plants (1820±900 nmol/g dry leaf). the concentrations of these glycosides were found to be within the range described for native species and also were similar to an european cultivar, what makes possible its industrial use for the cardenolides production.
Antimicrobial activity of Trembleya laniflora , Xyris platystachia and Xyris pterygoblephara
Ventura, Claiton Pires;Oliveira, Alaíde Braga de;Braga, Fern?o Castro;
Revista Brasileira de Farmacognosia , 2007, DOI: 10.1590/S0102-695X2007000100005
Abstract: trembleya laniflora (d. don) cogn. (melastomataceae), xyris platystachia alb. nilss. (xyridaceae) and xyris pterygoblephara kunth., brazilian species collected from a biodiversity hotspot for conservation priority, had their antimicrobial activity evaluated against standardized strains of staphylococcus aureus and micrococcus luteus, by the agar diffusion assay. all extracts, assayed in the concentration of 2000 μg/disc, were active against m. luteus, whereas s. aureus growth was inhibited only by t. laniflora leaves and x. platystachia aerial parts. fractionation of the extracts by partition between immiscible solvents resulted in active fractions from extracts originally inactive against s. aureus. activity was mainly found in low and medium polar fractions. the extract of t. laniflora leaves was also fractionated by silica gel column chromatography and both the hplc fingerprint and antimicrobial activity of the obtained fractions were distinct of those originated from the partition process.
Plant-Derived Antimalarial Agents: New Leads and Efficient Phytomedicines. Part II. Non-Alkaloidal Natural Products
Ronan Batista,Ademir De Jesus Silva Júnior,Alaíde Braga De Oliveira
Molecules , 2009, DOI: 10.3390/molecules14083037
Abstract: Malaria is still the most destructive and dangerous parasitic infection in many tropical and subtropical countries. The burden of this disease is getting worse, mainly due to the increasing resistance of Plasmodium falciparum against the widely available antimalarial drugs. There is an urgent need for new, more affordable and accessible antimalarial agents possessing original modes of action. Natural products have played a dominant role in the discovery of leads for the development of drugs to treat human diseases, and this fact anticipates that new antimalarial leads may certainly emerge from tropical plant sources. This present review covers most of the recently-published non-alkaloidal natural compounds from plants with antiplasmodial and antimalarial properties, belonging to the classes of terpenes, limonoids, flavonoids, chromones, xanthones, anthraquinones, miscellaneous and related compounds, besides the majority of papers describing antiplasmodial crude extracts published in the last five years not reviewed before. In addition, some perspectives and remarks on the development of new drugs and phytomedicines for malaria are succinctly discussed.
Optimization of diterpenes bioconversion process by the fungus Cephalosporium aphidicola
Takahashi, Jacqueline Aparecida;Barroso, Henrique de Almeida;Oliveira, Alaíde Braga de;
Brazilian Journal of Microbiology , 2000, DOI: 10.1590/S1517-83822000000200003
Abstract: parameters for a more efficient biotransformation of diterpene-like compounds by the fungus cephalosporium aphidicola were established by carrying out microscale feedings at several conditions. experiments were guided by thin layer chromatography and gas chromatography analysis. it was observed that the substrate should be added in ethanol at concentrations between 15 to 30 mg per 100 ml of medium. the extraction of the product showed to be more efficient when carried out from both mycelia and broth and using ethylacetate as the extracting solvent. the experiment should be stopped six days after feeding the substrate to the fungus for the best product yield.
Optimization of diterpenes bioconversion process by the fungus Cephalosporium aphidicola
Takahashi Jacqueline Aparecida,Barroso Henrique de Almeida,Oliveira Alaíde Braga de
Brazilian Journal of Microbiology , 2000,
Abstract: Parameters for a more efficient biotransformation of diterpene-like compounds by the fungus Cephalosporium aphidicola were established by carrying out microscale feedings at several conditions. Experiments were guided by thin layer chromatography and gas chromatography analysis. It was observed that the substrate should be added in ethanol at concentrations between 15 to 30 mg per 100 ml of medium. The extraction of the product showed to be more efficient when carried out from both mycelia and broth and using ethylacetate as the extracting solvent. The experiment should be stopped six days after feeding the substrate to the fungus for the best product yield.
Synthesis of triazol derivatives of lupeol with potential antimalarial activity Síntese de derivados triazólicos com potencial atividade antimalárica a partir do lupeol
Tatiane Freitas Borgati,Guilherme Rocha Pereira,Geraldo Célio Brand?o,Alaíde Braga de Oliveira
Orbital : the Electronic Journal of Chemistry , 2012,
Abstract: The goal of this project is synthesize and characterization of derivatives of lupeol and evaluated antimalarial activity. Historically, plants are important source of antimalarial medicines, highlighting quinine (1) (Figure 1), an important alkaloid from the Cinchona calisaya bark. This compound was an important model for cloroquine synthesis, a drug that was widely used in malaria treatment. In addition, one of the principal medicines used today is artemisinine, isolated from the Chinese plant Artemisia annua L (2) (Figure 1), and their semi synthetic derivatives (artesunate, artemeter, arteter). However, the malaria parasite has already shown resistance to most of these current drugs and the search for new candidates is essential. Lupeol (3) (Figura 1) is a compound that occurs in many plant species and discloses antimalarial, antiinflamatoryl and antitumoral activities. Considering its potential as a lead antimalarial molecule, we focused our work in the synthesis of new lupeol derivatives with increased antimalarial activity(scheme 1). Relata-se nesse trabalho a síntese e caracteriza o de derivados do luepol para avalia o da atividade antimalárica. Historicamente, as plantas s o uma importante fonte de fármacos antimaláricos destacando-se a quinina (1) (Figura 1), um alcalóide extraído da casca da Cinchona calisaya, que serviu de modelo para síntese da cloroquina, um dos fármacos que foi mais amplamente empregado no tratamento da malária. Atualmente, os principais fármacos em uso clínico s o a artemisinina, isolada da planta chinesa Artemisia annua L. (2) (Figura 1), e seus derivados semi-sintéticos (artesunato, artemeter, arteter). A busca de novos antimaláricos é de alta relevancia, uma vez que já se registrou resistência do P. falciparum à artemisinina e derivados. Sabe-se que o lupeol (3) (Figura 1) ocorre em várias espécies vegetais e possui atividades antimalárica, anti-inflamatória e antitumoral. Dessa forma, ele foi escolhido como material de partida para a síntese de novas drogas com potencial atividade antimalárica. Prop e-se com esse projeto modifica es químicas no lupeol, incluindo a incorpora o da 7- cloroquinolina à estrutura deste, via síntese de híbridos triazólicos. Os métodos de síntese utilizados s o fundamentados em rea es clássicas da química organica (Esquema 1) como, substitui o nucleofílica, e a cicloadi o entre um alcino terminal e uma azida organica catalisada por cobre, também conhecida como “rea o click “ (CuAAC). As substancias foram sintetizadas com rendimentos variando entre 40 e 80%. Os produtos obt
Cytotoxicity of Wedelia paludosa D.C. extracts and constituents
Batista, Ronan;Brand?o, Geraldo C.;Braga, Fern?o C.;Oliveira, Alaíde B.;
Revista Brasileira de Farmacognosia , 2009, DOI: 10.1590/S0102-695X2009000100009
Abstract: wedelia paludosa d.c. (asteraceae) is an ornamental species occurring in many regions of brazil. aiming to find new cytotoxic compounds, the hydromethanol extract of w. paludosa (hme), as well as the dichloromethane (df) and water (wf) fractions resulting from its partition, were submitted to the brine shrimp lethality bioassay (bslb) in order to evaluate their cytotoxicity. dichloromethane fraction (df) was shown to be the most cytotoxic fraction (lc50 = 140.6 μg/ml), and its analysis by reversed phase high performance liquid chromatography (rp-hplc) revealed ent-kaurenoic (1, 6.22 ± 0.23%) and grandiflorenic (2, 3.22 ± 0.31%) acids as important constituents. hme (lc50 = 980 μg/ml), df (lc50 = 140.6 μg/ml), 1 (lc50 = 15.9 μg/ml) and 2 (lc50 = 29.8 μg/ml) were found to be cytotoxic, while the water fraction (wf, lc50 >> 1000 μg/ml) was inactive. as conclusion, the cytotoxicity observed for hme and df is mainly due to the presence of 1 and 2 in their constitution.
Análise de naftoquinonas em extratos brutos de raízes de Zeyheria montana M. (bolsa-de-pastor)
Jácome, Rose Lisieux. R. Paiva;Oliveira, Alaíde Braga de;Raslan, Délio S.;Müller, Andreas;Wagner, Hildebert;
Química Nova , 1999, DOI: 10.1590/S0100-40421999000200004
Abstract: four naphthoquinones, lapachol, a-lapachone, dehydro-a-lapachone and 4-hydroxy-a-lapachone were isolated from the ethanol extract of zeyheria montana m. roots (bignoniaceae) and were identified by spectroscopic methods. these naphthoquinones, except 4-hydroxy-a-lapachone, were quantified by hplc, in the crude ethanol extracts of z. montana roots. the separation of lapachol, a-lapachone and dehydro-a-lapachone was achieved and these compounds were identified in the chromatograms by their retention times and by their on line uv-spectra. the quantification of the three naphthoquinones, in four different samples showed medium contents of 11,0 mg of lapachol, 6,1 mg of a-lapachone and 4,3 mg of dehydro-a-lapachone, in 100 mg of z.montana roots.
Estudo químico e perfil cromatográfico das cascas de Aspidosperma parvifolium A. DC. ("pau-pereira")
Jácome, Rose Lisieux R. Paiva;Oliveira, Alaíde Braga de;Raslan, Délio S.;Wagner, Hildebert;
Química Nova , 2004, DOI: 10.1590/S0100-40422004000600011
Abstract: four known alkaloids, uleine, epiuleine, apparicine and desmethyluleine, besides the isoprenoids lupeol and stigmasterol were isolated from the stem bark of aspidosperma parvifolium. their identification was based on spectroscopic analysis (uv, ir, 1h-nmr, 13c-nmr, ms). the chromatographic profile of the ethanolic extract was obtained by hplc and uleine, epiuleine and apparicine were identified in the extract.
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