916 resultados para thin-layer chromatography


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Objetivo: avaliar as repercussões do diabete materno sobre o perfil fosfolipídico pulmonar de fetos de ratas com diabete moderado e grave pelas dosagens de lecitina (L), esfingomielina (E), fosfatidil-glicerol (PG), fosfatidil-inositol (PI) e relações L/E e PG/PI. Métodos: foram utilizadas 54 ratas Wistar, em idade reprodutiva, introduzidas na seqüência experimental de diabete e prenhez¹. O diabete foi induzido por aloxana (42 mg/kg de peso, iv) e compostos três grupos: controle, diabete moderado (DM, glicemia entre 120 e 200 mg/dl) e diabete grave (DG, níveis superiores a 200 mg/dl). Realizou-se cesárea no 21º dia, os pulmões fetais foram macerados, reunidos em pool e os fosfolipídios dosados por cromatografia em camada delgada unidirecional. Resultados: os pulmões dos filhotes das ratas com diabete moderado tiveram maior peso (0,159 g) e menor concentração de PG (3,0 µg/ml) e PI (3,4 µg/ml) que o grupo controle (0,155 g; 6,8 e 6,7 µg/ml), e as mesmas relações L/E (2,2) e PG/PI (2,0); os pulmões dos filhotes das ratas com diabete grave tiveram menor peso (0,145 g), os mesmos valores das relações L/E (1,9) e PG/PI (2,1) e menor valor de PI (5,1 µg/ml) que o grupo controle. Conclusões: 1) o retardo do amadurecimento pulmonar dos recém-nascidos de ratas com diabete moderado é explicado pelo maior peso pulmonar associado à menor concentração de PG e PI; 2) a aceleração do amadurecimento pulmonar dos recém-nascidos de ratas com diabete grave é explicada pelo menor peso pulmonar associado à mesma concentração de PG e PI.

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The objective was to determine the distribution in pea seedling of GA (by thin layer chromatography) and IAA (by HPLC). Three samples of 30 7/day-old seedlings were sectioned into: apical meristem + plumular hook; stem elongation zone; stem non-elongation zone; cotyledons; root non-elongation zone; root tip. The material was frozen in liquid N and stored at -80 degrees C. The stem elongation zone, the apical meristem+plumular hook and the root tip had low IAA, whereas the stem non-elongation zone and root non-elongation zone had high IAA content. The stem elongation zone and apical meristem plumular hook had high GA, while root non-elongation zone had the lowest GA content.

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center dot Background and Aims Nectar production in the Bignoniaceae species lacking a nectariferous functional disc is ascribed to trichomatic glands around the ovary base and/or on the inner corolla wall. Nevertheless, knowledge about the secretion and function of these glands is very incomplete. The purpose of this paper is to study, from a developmental viewpoint, the ultrastructure, histochemistry and secretory process of the peltate trichomes on the ovary of Zeyheria montana, a species in the Bignoniaceae which has a rudimentary disc.center dot Methods Samples of the gynoecium at various developmental stages were fixed and processed for light and electron microscopy. Histochemistry and cytochemistry tests were performed to examine the chemical composition of exudates. Thin layer chromatography was used to determine the presence of alkaloids and terpenes in gynoecium and fruit extracts, and in fresh nectar stored in the nectar chamber.center dot Key Results Peltate trichomes at different developmental stages appear side by side from floral budding up to pre-dispersal fruit. Large plastids with an extensive internal membrane system consisting of tubules filled with lipophilic material, abundant smooth endoplasmic reticulum, few Golgi bodies, lipophilic deposits in the smooth endoplasmic reticulum and mitochondria, and scattered cytoplasmic oil droplets are the main characteristics of mature head cells. The secretion which accumulates in the subcuticular space stains positively for hydrophilic and lipophilic substances, with lipids prevailing for fully peltate trichomes. Histochemistry and thin layer chromatography detected terpenes and alkaloids. Fehling's test to detect of sugars in the secretion was negative.center dot Conclusions the continuous presence and activity of peltate trichomes on the ovary of Z. montana from early budding through to flowering and fruiting set, and its main chemical components, alkaloids and terpenes, suggest that they serve a protective function and are not related to the floral nectar source or to improving nectar quality.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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An Aspergillus giganteus strain was isolated as an excellent producer of xylanase associated with low levels of cellulase. Optimal xylanase production was obtained in liquid VOGEL medium containing xylan as carbon source, pH 6.5 to 7.0, at 25degreesC and. under shaking at 120 rpm during 84h. Among the several carbon sources tested, higher xylanase production was verified in xylan, xylose, sugar-cane bagasse, wheat bran and corn cob cultures, respectively. Optimal conditions for activity determination were 50degreesC and pH 6.0. The xylanolytic complex of A. giganteus showed low thermal stability with T-50 of 2 h, 13 min and I min when it was incubated at 40, 50 and 60degreesC, respectively, and high stability from pH 4.5 to 10.5, with the best interval between 7.0 to 7.5. This broad range of stability in alkali pH indicates a potential applicability in some industrial processes, which require such condition. Xylanolytic activity of A. giganteus was totally inhibited by Hg+2, Cu+2 and SDS at 10 mm. The analysis of the products from the oat spelts xylan hydrolysis through thin-layer chromatography indicated endoxylanase activity, lack of debranching enzymes and P-xylosidase activity in assay conditions.

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The keratin is not degraded by common enzyme, keratinases have the ability to degrade native keratin and others insoluble enzymes. In the present work was Studied keratinase produced by Streptomyces sp LMI-1 isolated from industrial plant of poultry processing. The enzyme degraded 87% of feathers after 120 h, it was stimulated by Ba(2+) and inhibited by Ca(2+), Mn(2+), EDTA and Hg(+). The optimum pH and temperature for the enzyme was 8.5 and 60 degrees C, respectively. The enzyme was stable after 2 hours at 50 degrees C. The culture broth analysis by thin layer chromatography showed presence of amino acids serine, methionine, proline, tyrosine and leucine after 72 hours of incubation. The microorganism showed potential for use in industrial process because of higher enzyme production and feathers degradation.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Background: Endurance training increases insulin-stimulated muscle glucose transport and leads to improved metabolic control in diabetic patients.Objective: To analyze the effects of endurance training on the early steps of insulin action in muscle of rats. Design: Male rats submitted to daily swimming for 6 weeks were compared with sedentary controls. At the end of the training period, anesthetized animals received an intravenous (i.v.) injection of insulin and had a fragment of their gastrocnemius muscle excised for the experiments.Methods: Associations between insulin receptor, insulin receptor substrates (IRS)-1 and -2 and phosphatidylinositol 3-kinase (PI3-kinase) were analyzed by immunoprecipitation and immunoblotting. Akt-1 serine phosphorylation and specific protein quantification were detected by immunoblotting of total extracts, and IRS-1/IRS-2-associated PI3-kinase activity were determined by thin-layer chromatography.Results: Insulin-induced phosphorylation of IRS-1 and IRS-2 increased respectively by 1.8-fold (P < 0.05) and 1.5-fold (P < 0.05), whereas their association with PI3-kinase increased by 2.3-fold (P < 0.05) and 1.9-fold (P < 0.05) in trained rats as compared with sedentary controls, respectively. The activity of PI3-kinase associated with IRS-1 and IRS-2 increased by 1.8-fold (P < 0.05) and 1.7-fold (P < 0.05) respectively, in trained rats as compared with their untrained counterparts. Serine phosphorylation of Akt-1/PKB increased 1.7-fold (P < 0.05) in trained rats in response to insulin. These findings were accompanied by increased responsiveness to insulin as demonstrated by a reduced area under the curve for insulin during an i.v. glucose tolerance test, by increased glucose disappearance rate during an insulin tolerance test, and by increased expression of glucose transporter-4.Conclusions: the increased responsiveness to insulin induced by chronic exercise in rat skeletal muscle may result, at least in part, from the modulation of the insulin signaling pathway at different molecular levels.

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Este trabalho descreve o desenvolvimento de metodologia para o controle de qualidade dos extratos etanólicos e infusão de Turnera diffusa Willd. ex Schult., Turneraceae, usando como marcadores os compostos fenólicos. Essa espécie é usada popularmente como afrodisíaca e antiulcerogênica. Foram usadas técnicas cromatográficas: CLAE acoplada com detector de ultravioleta e cromatografia em camada delgada. Foram detectados flavonóides como os principais componentes da planta.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The prevalence of Mycobacterium bovis and other mycobacterial species in livestock specimens and milk was evaluated. An emphasis was placed upon the distribution of these organisms in milk that is readily available to the public that was either untreated, pasteurized, or treated using ultra high temperature. Twenty-two pathologic specimens from livestock (bovine, swine and bubaline) in five Brazilian states and 128 bovine milk samples from retail markets in the State of São Paulo were examined for mycobacteria. Identification was made by classical biochemical tests, thin layer chromatography of mycolic acids and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Mycobacteria were isolated from 15 (68.2%) caseous lesions and from 23 (18%) milk samples. Eleven isolates were identified as M. bovis, and the remaining 27 nontuberculous mycobacterial isolates were represented by five species and six unidentified rapidly growing mycobacterial strains. The data demonstrate that animal products in Brazil are frequent reservoirs of mycobacteria and may pose a risk to the public.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This paper reports the separation and identification of indole alkaloids, steroids and triterpenoids from the ethanolic extracts of Tabernaemontana hilariana (Apocynaceae). The alkaloidal fractions from the ethanolic extracts obtained (root barks, green fruits, ripe fruits and seeds) were fractionated and analysed by thin-layer chromatography, capillary gas chromatography-flame ionization detection (cGC-FID) as well as by high-resolution gas chromatography-mass spectrometry (HRGC-MS). 3-Hydroxycoronaridine, ibogamine, coronaridine pseudoindoxyl, coronaridine, catharanthine, voacangine hydroxyindolenine, voacangine pseudoindoxyl, tabernanthine, tetraphyllicine, 3-hydroxyvoacangine, voacangine, isovoacangine and 3-oxocoronaridine were identified. The insoluble fraction of ethanolic extracts obtained from the root barks and green fruits were analysed and ten aliphatic constituents were also identified by cGC-FID and HRGC-MS. (C) 1998 Elsevier B.V. B.V. All rights reserved.

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The effects of Alchornea glandulosa ethyl acetate fraction (AGF) on hydrogen peroxide (H2O2), nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) production in peritoneal macrophages activated with lipopolysaccharide (LPS) or phorbol myristate acetate (PMA) were investigated. Analysis by thin layer chromatography (TLC) of AGF showed several constituents, including flavonoids, which may have anti-inflammatory activity. Inhibitory effects of the fraction in H2O2 and NO production ranged from 8.59 +/- 7.84% to 70.56 +/- 4.16% and from 16.06 +/- 3.65% to 38.73 +/- 3.90%, respectively. The TNF-alpha production was only partially inhibited in the tested concentrations (12.21 +/- 6.23%-15.16 +/- 0.96%). According to these results, it is suggested that AGF has anti-inflammatory activity. This medicinal plant may have therapeutic potential in the control of inflammatory disorders.