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Search Results: 1 - 10 of 276983 matches for " Joyce Kelly R. da;Maia "
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Antioxidant capacity and biological activity of essential oil and methanol extract of Conobea scoparioides (Cham. & Schltdl.) Benth.
Rebelo, Monaliza M.;Silva, Joyce Kelly R. da;Andrade, Eloísa Helena A.;Maia, José Guilherme S.;
Journal of the Brazilian Chemical Society , 2009, DOI: 10.1590/S0103-50532009000600005
Abstract: the essential oils of the sub-aquatic plant conobea scoparioides (fresh and dried previously) showed yields of 3.4 and 3.3%, respectively. the main identified constituents were thymol methyl ether (39.6 and 47.7%), thymol (40.0 and 26.4%), α-phellandrene (12.1 and 14.3%) and p-cymene (1.5 and 1.7%), totalizing more than 90% of the oils. the dpph radical scavenging activity (ec50) of the oils and extract was 46.7 ± 3.6 μg ml-1 in the fresh plant (cso-f), 56.1 ± 2.4 μg ml-1 in the dried plant (cso-d), and 23.0 ± 2.2 μg ml -1 in the methanol extract. the extract (cse-d)value is comparable to bht (19.8 ± 0.5 μg ml-1) used as antioxidant standard. the mean value of the oils is twice smaller but equally important as antioxidant agent. the mean amount of total phenolics (tp, 124.6 ± 8.7 mg gae per g) and the trolox equivalent (teac, 144.1 ± 4.9 mg te per g) of the methanol extract confirmed the significant antioxidant activity of c. scoparioides. similarly, in the brine shrimp bioassay (artemia salina) the mean value of the lethal concentration for the oils (lc50, 7.7 ± 0.3 μg ml-1) was ten times higher than the methanol extract (lc50, 77.6 ± 7.1 μg ml-1) showing important biological activity.
Antioxidant capacity and biological activity of essential oil and methanol extract of Hyptis crenata Pohl ex Benth
Rebelo, Monaliza M.;Silva, Joyce Kelly R. da;Andrade, Eloísa Helena A.;Maia, José Guilherme S.;
Revista Brasileira de Farmacognosia , 2009, DOI: 10.1590/S0102-695X2009000200009
Abstract: the essential oils of fresh and dried leaves and fine stems of hyptis crenata furnished the following yields: 1.4% and 0.9%. the main volatile constituents were ±-pinene (22.0%; 19.5%), 1,8-cineole (17.6%; 23.2%), 2-pinene (17.0%; 13.8%), camphor (4.7%; 11.6%), limonene (5.4%; 4.4%) and 3-terpinene (3.5%; 2.4%), totalizing more than 70% in the oils. the dpph radical scavenging activity (ec50, 16.7 + 0.4 μg/ml) of the methanol extract was comparable to bht (19.8 ± 0.5 μg/ml) showing a significant antioxidant activity. the oils showed low activities. the amount of total phenolics (tp, 373.0 + 15.9 mg gae/g) and trolox equivalent (teac, 226.8 + 0.5 mg te/g) confirmed the antioxidant activity of the methanol extract that can be attributed to the presence of polar phenolic compounds. in the brine shrimp bioassay the lethal concentrations (lc50) for the oil and methanol extract were 6.7 + 0.2 μg/ml and 13.0 + 3.7 μg/ml, respectively, providing important evidence of their biological activities.
Essential oil composition of Croton palanostigma Klotzsch from north Brazil
Brasil, Davi do Socorro B.;Muller, Adolfo Henrique;Guilhon, Giselle Maria S. P.;Alves, Cláudio Nahum;Andrade, Eloísa Helena A.;Silva, Joyce Kelly R. da;Maia, José G. S.;
Journal of the Brazilian Chemical Society , 2009, DOI: 10.1590/S0103-50532009000600026
Abstract: the essential oils of leaves, twigs, branches, trunk bark and fruits of croton palanostigma were analyzed by gc and gc-ms. the main compounds found in the oil of the leaves were linalool (25.4%), (e)-caryophyllene (21.0%), methyleugenol (17.2%) and β-elemene (6.0%); in the oil of the twigs were α-pinene (41.4%), limonene (29.0%), sabinene (11.5%) and β-pinene (5.7%); in the oil of the branches were methyleugenol (24.1%), (e)-methylisoeugenol (15.3%), α-pinene (11.2%) and (e)-caryophyllene (8.5%); in the oil of the trunk bark were a-pinene (31.6%), methyleugenol (25.6%) and (e)-methylisoeugenol (23.7%); and in the oil of the fruits were linalool (42.7%), methyleugenol (16.3%) and β-elemene (6.4%). statistical analysis showed that the leaves and fruit, and the branches and trunk bark, have significant similarities between them. in addition, the trunk bark oil has high brine shrimp larvicidal activity (lc50, 3.71 ± 0.01 mg ml-1).
Antioxidant capacity and larvicidal activity of essential oil and extracts from Lippia grandis
Damasceno, Evelyn Ivana T.;Silva, Joyce Kelly R.;Andrade, Eloisa Helena A.;Sousa, Pergentino José C.;Maia, José Guilherme S.;
Revista Brasileira de Farmacognosia , 2011, DOI: 10.1590/S0102-695X2011005000013
Abstract: 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.
Antioxidant capacity and larvicidal activity of essential oil and extracts from Lippia grandis
Evelyn Ivana T. Damasceno,Joyce Kelly R. Silva,Eloisa Helena A. Andrade,Pergentino José C. Sousa
Revista Brasileira de Farmacognosia , 2011,
Abstract: 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.
Chemistry and Biological Activities of Terpenoids from Copaiba (Copaifera spp.) Oleoresins
Lidiam Maia Leandro,Fabiano de Sousa Vargas,Paula Cristina Souza Barbosa,Jamilly Kelly Oliveira Neves,José Alexsandro da Silva,Valdir Florêncio da Veiga-Junior
Molecules , 2012, DOI: 10.3390/molecules17043866
Abstract: Copaiba oleoresins are exuded from the trunks of trees of the Copaifera species (Leguminosae-Caesalpinoideae). This oleoresin is a solution of diterpenoids, especially, mono- and di-acids, solubilized by sesquiterpene hydrocarbons. The sesquiterpenes and diterpenes (labdane, clerodane and kaurane skeletons) are different for each Copaifera species and have been linked to several reported biological activities, ranging from anti-tumoral to embriotoxic effects. This review presents all the substances already described in this oleoresin, together with structures and activities of its main terpenoids.
Preventive effect of fluoridated orthodontic resins subjected to high cariogenic challenges
Passalini, Paula;Fidalgo, Tatiana Kelly da Silva;Caldeira, Erika Machado;Gleiser, Rogerio;Nojima, Matilde da Cunha Gon?alves;Maia, Lucianne Cople;
Brazilian Dental Journal , 2010, DOI: 10.1590/S0103-64402010000300006
Abstract: the aim of the present study was to evaluate the in vitro caries preventive effect of fluoridated orthodontic resins under ph cycling with two types of acid demineralizing saliva. brackets were bonded to 60 bovine incisors, using either transbond plus color change (n=30) or orthodontic fill magic (n=30) orthodontic resins. each group of resin was divided into 3 subgroups (n=10): immersion in remineralizing artificial saliva for 14 days, ph cycling with high cariogenic challenge in acid saliva with ph 5.5, and acid saliva with ph 4.5. after 14 days of ph cycling, the caries preventive effect on the development of white spot lesion was evaluated considering the presence of inhibition zones to white spot lesions using two scores: 0= absence and 1= presence. kruskal wallis and mann-whitney tests (a=0.05) were used. formation of white spot lesions was observed only under ph cycling using acid saliva with ph 4.5; with transbond plus color change being significantly more effective (p<0.05) in preventing the appearance of white spot lesions effect than orthodontic fill magic. the acidity of the demineralizing solution influenced the formation of white spot lesions around orthodontic brackets under highly cariogenic conditions. transbond plus color change resin presented higher caries preventive effect than orthodontic fill magic.
Mechanical properties of one and two-step fluoridated orthodontic resins submitted to different pH cycling regimes
Passalini, Paula;Fidalgo, Tatiana Kelly da Silva;Caldeira, Erika Machado;Gleiser, Rogério;Nojima, Matilde da Cunha Gon?alves;Maia, Lucianne Cople;
Brazilian Oral Research , 2010, DOI: 10.1590/S1806-83242010000200012
Abstract: the aim of this study is to assess the in vitro shear bond strength and adhesive remnant index (ari) of one and two-step fluoridated orthodontic resins under conditions that simulate high cariogenic challenge. edgewise brackets for maxillary central incisors were randomly bonded to 80 bovine incisors, using either transbondtm plus color change orthodontic resin and a self-etching primer adhesive (g1; n = 40) or orthodontic fill magic with a conventional acid-etch technique (g2; n = 40). each group of resin (n = 10) was divided into: immediate shear (a- pre-cycling control), immersion in artificial remineralizing saliva (neutral saliva) for 14 days (b- post-cycling control) and ph cycling with high cariogenic challenge (c- acid saliva with ph 5.5 and d- acid saliva with ph 4.5). after 14 days of ph cycling, the shear bond strength and ari were evaluated. considering the shear bond strength, transbondtm plus color change resin was stronger than orthodontic fill magic when it was submitted to high cariogenic challenge (p < 0.05). also transbondtm plus color change resin showed better adhesion to enamel than orthodontic fill magic, in all situations evaluated (p < 0.05). it could be concluded that transbondtm plus color change resin presented better shear bond strength and adhesive remnant index when submitted to high cariogenic challenge, in comparison with orthodontic fill magic.
The Rotation of Binary Systems with evolved Components
J. R. De Medeiros,J. R. P. Da Silva,M. R. G. Maia
Physics , 2002, DOI: 10.1086/342613
Abstract: In the present study we analyze the behavior of the rotational velocity, vsini, for a large sample of 134 spectroscopic binary systems with a giant star component of luminosity class III, along the spectral region from middle F to middle K. The distribution of vsini as a function of color index (B-V) seems to follow the same behavior as their single counterparts, with a sudden decline around G0III. Blueward of this spectral type, namely for binary systems with a giant F-type component, one sees a trend for a large spread in the rotational velocities, from a few km/s to at least 40km/s. Along the G and K spectral regions there is a considerable number of binary systems with moderate to moderately high rotation rates. This reflects the effects of synchronization between rotation and orbital motions. These rotators have orbital periods shorter than about 250 days and circular or nearly circular orbits. Except for these synchronized systems, the large majority of binary systems with a giant component of spectral type later than G0III are composed of slow rotators.
Estabilidade da polpa do bacuri (Platonia insignis Mart.) congelada por 12 meses
Silva, Virlane Kelly Lima da;Figueiredo, Raimundo Wilane de;Brito, Edy Sousa de;Maia, Geraldo Arraes;Sousa, Paulo Henrique Machado de;Figueiredo, Evania Altina Teixeira de;
Ciência e Agrotecnologia , 2010, DOI: 10.1590/S1413-70542010000500030
Abstract: the objective of this work was to process and evaluate the stability of the bacuri (platonia insignis mart.) pulp submitted to freezing for 12 months. during the storage period there were significant changes in the physiochemical characteristics of the pulp as for the content of total soluble solids, ph, water activity, total and reducing sugars, vitamin c, polimer and oligomeric phenolic compounds , total and soluble pectin and color l, the a*, b *,while total acidity and soluble solids varied with the storange period. the dimers phenolic compounds incresead with the time. according to the results, the bacuri pulp cannot be considered a good source of vitamin c, but it presents low contents of phenolic compounds characterizing the pulp as little astringent, thus showing potential for the processing. the microbiological quality was not altered during the storage period indicating the efficiency of freezing for maintaining the physiochemical and microbiological characteristics of the bacuri pulp.
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