56 resultados para Thymol


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Turnera diffusa Willd. var. afrodisiaca (Ward) Urb. (syn. T. aphrodisiaca) belongs to the family of Turneraceae and is an aromatic plant growing wild in the subtropical regions of America and Africa. It is widely used in the traditional medicine as e.g. anti-cough, diuretic, and aphrodisiac agent. This work presents a 3 min chromatographic analysis using low-pressure (LP) gas chromatography (GC)-ion-trap (IT) mass spectrometry (MS). The combination of a deactivated 0.6 m x 0.10 mm i.d., restrictor with a wide-bore CP-Wax 52 capillary column (10 m x 0.53 mm i.d., 1 mum) reduces the analysis time by a factor of 3-7 in comparison to the use of a conventional narrow bore column. Chromatographic conditions have been optimized to achieve the fastest separation with the highest signal/noise ratio in MS detection. These results allow fast and reliable quality control of the essential oil to be achieved. (C) 2003 Elsevier B.V. All rights reserved.

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Objective. The purpose of this study was to evaluate the release of formaldehyde by some root canal filling materials. Study design. Two older endodontic sealers, AH 26 and Endomethasone, and 2 recently available sealers, AH Plus and Top Seal, were analyzed. Infrared and electronic spectroscopy were used to determine formaldehyde content after set of the materials. Results. Analysis showed that the AH 26 and Endomethasone sealers released formaldehyde. Although the AH Plus and Top Seal sealers have similar chemical composition, they released formaldehyde in a minimal concentration. Conclusions. The AH 26 and Endomethasone sealers released formaldehyde after setting; however, a minimum release was observed for the AH Plus and Top Seal sealers. Copyright © 1999 by Mosby, Inc.

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After filling root canals, the healing process depends on the chemical composition or physical-chemical properties of the material used, among other factors. All root canal sealers, whether solid or plastic, are foreign matter for the body if they remain in permanent contact with apical and periapical tissues. As a result, the first organic reaction that occurs is an attempt to phagocytize the material. During phagocytosis, macrophages release a large number of cell mediators into the area, among which are cytokines that are essential in intercellular communication and in many physiological and pathophysiological processes. One of these cytokines is tumor necrosis factor-alfa (TNF-α), which acts through links to specific receptors on the cell membrane initiating a cascade of events leading to induction, activation, or inhibition of numerous cytokine-regulated genes in the cell nucleus. The release of TNF-α in a cell culture of mouse peritoneal macrophages incubated with three concentrations (25, 50, and 100 mg/ml) of two endodontic sealers was measured. The solutions containing the calcium hydroxide-based root canal sealer (Sealapex) released fewer units of TNF-α than solutions containing the zinc oxide and eugenol-based sealer (Endomethasone).

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The purpose of this study was to evaluate the influence of coronal leakage on the healing of dogs' periapical tissues after root canal filling, post space preparation and protection or not with a temporary sealer plug. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta-percha points and Endomethasone or CRCS sealers. After post space preparation, the remaining filling material was protected or not with a plug of temporary Coltosol sealer and exposed to the oral environment for 90 days. Thereafter, the animals were sacrificed and the specimens were removed and prepared for histomorphological and histobacteriological analysis. The findings revealed 35% of microbial leakage in the groups without plugs and 15% of leakage in the groups with plugs. Statistical analysis showed that the use of a Coltosol plug improved significantly the histomorphological results regardless of the type of root canal sealer (p=0.05) and that CRCS and Endomethasone sealers showed similar results (p>0.05).

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The leaves and thin branches of Lippia grandis Schauer, Verbenaceae, are used for flavoring of food in the Brazilian Amazon, as substitute for oregano. In this study the constituents of the essential oil were identified and the antioxidant capacity and larvicidal activity of the oil and methanol extract and its sub-fractions were evaluated. A sensory evaluation was determined in view of absence of toxicity. The oil showed a yield of 2.1% and its main constituents were thymol (45.8%), p-cymene (14.3%), γ-terpinene (10.5%), carvacrol (9.9%) and thymol methyl ether (4.8%), totalizing 85%. The DPPH radical scavenging activity showed values for the EC50 between 9.0 and 130.5 µg mL-1 and the TEAC/ABTS values varied from 131.1 to 336.0 mg TE/g, indicating significant antioxidant activity for the plant. The total phenolic content ranged from 223.0 to 761.4 mg GAE/g, contributing to the antioxidant activity observed. The crude extracts inhibited the bleaching of β-carotene and the oil showed the greatest inhibition (42.5%). The oil (LgO, 7.6±2.4 µg mL-1) showed strong larvicidal activity against the brine shrimp bioassay. The sensory evaluation was highly satisfactory in comparison to oregano. The results are very promising for the use of L. grandis in seasoning and antioxidant products.

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Os óleos essenciais da planta sub-aquática Conobea scoparioides (fresca e previamente seca) apresentaram rendimentos de 3,4 e 3,3%, respectivamente. Os principais constituintes identificados foram o éter metílico do timol (39,6 e 47,7%), timol (40,0 e 26,4%), α-felandreno (12,1 e 14,3%) e p-cimeno (1,5 e 1,7%), totalizando mais de 90% nos referidos óleos. A concentração de seqüestro do radical DPPH (CE50) dos óleos e extrato foi de 46,7 ± 3,6 µg mL-1 para a planta fresca (CsO-f), de 56,1 ± 2,4 µg mL-1 para a planta seca (CsO-d), e de 23,0 ± 2,2 µg mL-1 para o extrato metanólico (CsE-d). O valor do extrato é comparável ao BHT (19,8 ± 0,5 µg mL-1), usado como padrão antioxidante. O valor médio dos óleos é duas vezes menor, mas igualmente importante como agente antioxidante. O teor de Fenólicos Totais (TP, 124,6 ± 8,7 mg GAE per g) e o Trolox Equivalente (TEAC, 144,1 ± 4,9 mg TE per g) do extrato metanólico confirmaram a significativa atividade antioxidante de C. scoparioides. Da mesma forma, nos bioensaios com larva de camarão (Artemia salina) o valor médio da concentração letal dos óleos (CL50, 7,7 ± 0,3 µg mL-1) foi dez vezes maior que no extrato metanólico (CL50, 77,6 ± 7,1 µg mL-1) mostrando importante atividade biológica.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Biologia Geral e Aplicada - IBB

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV