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| Registros recuperados: 104 | |
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| Gomes, Ana; Fernandes, Eduarda; Silva, Artur; Pinto, Diana; Santos, Clementina M.M.; Cavaleiro, José; Lima, José Costa. |
| 2-Styrylchromones are a small group of naturally occurring chromones, vinylogues of flavones (2-phenylchromones). Natural and synthetic 2-styrylchromones have been tested in different biological systems, showing activities with potential therapeutic applications. In particular, the potential and hitherto understudied antioxidant behavior of these compounds has been raised as a matter of interest. Thus the present work consisted in the study of the in vitro scavenging activities for reactive oxygen species (ROS) and reactive nitrogen species (RNS) of various 2-styrylchromone derivatives and structurally similar flavonoids. Some of the studied 2-styrylchromones proved to be extremely efficient scavengers of the different ROS and RNS, showing, in some cases,... |
| Tipo: Article |
Palavras-chave: 2-Styrylchromones; Reactive oxygen species; Reactive nitrogen species; Scavenging activity; Antioxidant activity. |
| Ano: 2007 |
URL: http://hdl.handle.net/10198/3922 |
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| Froufe, Hugo J.C.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.. |
| Wild mushrooms have been described as sources of natural antioxidants, particularly phenolic compounds. However, many other compounds present in wild mushrooms can also act as antioxidants (reducers), so whole extracts from a wide range of species need to be examined. To gain further knowledge in this area, the relationship between the antioxidant potential (scavenging effect and reducing power) and chemical composition of twenty three samples from seventeen Portuguese wild mushroom species was investigated. A wide range of analytical parameters reported by our research group (including ash, carbohydrates, proteins, fat, monounsaturated fatty acids, polyunsaturated fatty acids, saturated fatty acids, phenolics, flavonoids, ascorbic acid and -carotene)... |
| Tipo: Article |
Palavras-chave: Wild mushrooms; Chemical composition; Antioxidant activity; QCAR; PLS. |
| Ano: 2009 |
URL: http://hdl.handle.net/10198/2615 |
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| Ferreira, Isabel C.F.R.; Barros, Lillian; Soares, Maria Elisa; Bastos, Maria de Lourdes; Pereira, J.A.. |
| Olive trees (Olea europaea L. Cv. Cobranc¸osa) from the northeast of Portugal were sprayed with three different copper formulations [bordeaux mixture (copper sulphate + calcium hydroxide - 20% Cu), copper hydroxide (40% Cu) and copper oxychloride (50% Cu)] to control olive fungal diseases. The residues of copper in olive leaves, harvested at different times, were evaluated by atomic absorption spectrometry. At all the collection times, treated olive leaves had significantly higher copper contents, compared to the control. The different copper amounts in pesticide formulations lowered the leaves contents in total phenols and hence their antioxidant properties. Olive leaves sprayed with copper oxychloride possessed the highest copper levels and the lowest... |
| Tipo: Article |
Palavras-chave: Olea europaea; Olive leaves; Copper; Phenols; Antioxidant activity. |
| Ano: 2007 |
URL: http://hdl.handle.net/10198/749 |
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| HSU,CHIN-YUAN. |
| Free radicals induce numerous diseases by lipid peroxidation, protein peroxidation, and DNA damage. It has been reported that numerous plant extracts have antioxidant activities to scavenge free radicals. Whether Polygonum aviculare L. (Polygonaceae) has antioxidant activity is unknown. In this study, dried Polygonum aviculare L. was extracted by ethanol, and the extract was lyophilized. The antioxidant activities of extract powder were examined by free radical scavenging assays, superoxide radical scavenging assays, lipid peroxidation assays and hydroxyl radical-induced DNA strand scission assays. The results show that the IC50 value of Polygonum aviculare L. extract is 50 µg/ml in free radical scavenging assays, 0.8 µg/ml in superoxide radical scavenging... |
| Tipo: Journal article |
Palavras-chave: Antioxidant activity; Free radical; Phenolics; Lipid peroxidation; DNA damage Polygonum aviculare L. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000200010 |
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| Dandlen, S. Anahi; Lima, A. Sofia; Mendes, Marta D.; Miguel, M. Graça; Faleiro, M. Leonor; Sousa, Maria João; Pedro, Luis G.; Barroso, José G.; Figueiredo, A. Cristina. |
| The essential oils of Thymus caespititius, T. camphoratus, T. capitellatus, T. carnosus, T. pulegioides, T. zygis subsp. zygis and T. zygis subsp. sylvestris collected in diff erent regions of Portugal, including the Azores islands, were evaluated for preventing lipid peroxidation and scavenging free radicals, and hydroxyl and superoxide anions. T. zygis subsp. zygis oil possessed the best capacity for preventing lipid peroxidation (IC50 = 0.030 ± 0.003 mg/ml), immediately followed by the oils isolated from T. zygis subsp. sylvestris collected in diff erent regions of Portugal. IC50 values ranged from 0.066 ± 0.003 to 0.087 ± 0.001 mg/ml in oils isolated from samples from Alcanena and Duas Igrejas, respectively. The oils isolated from T. zygis subsp.... |
| Tipo: Article |
Palavras-chave: Thymus; Lamiaceae; Labiatae; Antioxidant activity; Essential oils. |
| Ano: 2010 |
URL: http://hdl.handle.net/10198/4474 |
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| Estevinho, Leticia M.; Pereira, A.P.; Moreira, Leandro; Dias, L.G.; Pereira, Ermelinda. |
| Phenolic compounds of dark and clear honeys from Trás-os-Montes of Portugal were extracted with Amberlite XAD-2 and evaluated for their antioxidant and antimicrobial activities. The antioxidant effect was studied using the in vitro test capacity of scavenge the 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical and of reducing power of iron (III)/ferricyanide complex. The antimicrobial activity was screened using three Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus, Staphylococcus lentus) and three Gram-negative bacteria (Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli). The results obtained from the partial identification of honey phenolic compounds by high-performance liquid chromatography with a diode array... |
| Tipo: Article |
Palavras-chave: Honey; Phenolic compounds; Antioxidant activity; Antimicrobial activity. |
| Ano: 2008 |
URL: http://hdl.handle.net/10198/2942 |
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| Desmarchelier,C.; Coussio,J.; Ciccia,G.. |
| Achyrocline satureioides (Lam.) DC. (Compositae) is a medicinal herb used in Argentina, Uruguay, Brazil and Paraguay for its choleretic, antispasmodic and hepatoprotective properties. The presence of the flavonoid quercetin and its derivatives, and of different phenolic acids such as caffeic, chlorogenic and isochlorogenic acids in the aerial parts of this plant has led us to study the antioxidant activity of its extracts using different bioassays. The inhibition of luminol-enhanced chemiluminescence by the aqueous and methanolic extracts was used to show that their total reactive antioxidant potential index (TRAP; in µM Trolox equivalents) was 91.0 ± 15.4 and 128.1 ± 20.1 µM, respectively, while the total antioxidant reactivity index (TAR) was calculated... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Achyrocline satureioides; Antioxidant activity; Luminol-enhanced chemiluminescence; Thiobarbituric acid-reactive substances; Hydroperoxide-initiated chemiluminescence; Lipid peroxidation; DNA damage; Reactive oxygen species. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000900010 |
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| Barreira, João C.M.; Ferreira, Isabel C.F.R.; Oliveira, M.B.P.P.; Pereira, J.A.. |
| The antioxidant properties of almond green husks (Cvs. Duro Italiano, Ferraduel, Ferranhês, Ferrastar and Orelha de Mula), chestnut skins and chestnut leaves (Cvs. Aveleira, Boa Ventura, Judia and Longal) were evaluated through several chemical and biochemical assays in order to provide a novel strategy to stimulate the application of waste products as new suppliers of useful bioactive compounds, namely antioxidants. All the assayed by-products revealed good antioxidant properties, with very low EC50 values (lower than 380 μg/mL), particularly for lipid peroxidation inhibition (lower than 140 μg/mL). The total phenols and flavonoids contents were also determined. The correlation between these bioactive compounds and DPPH (2,2-diphenyl-1-picrylhydrazyl)... |
| Tipo: Article |
Palavras-chave: Chestnut; Almond; By-products; Antioxidant activity; Total phenols. |
| Ano: 2010 |
URL: http://hdl.handle.net/10198/3036 |
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| SANTOS, S. N.; KAVAMURA, V.; CASTANHA, R. F.; ANDREOTE, F. D.; CARVALHO, J. E.; QUEIROZ, S. C. do N. de; MELO, I. S. de. |
| This investigation describes the anticancer, antioxidant and antimicrobial properties of the extracts of Combretum rupicola, a native plant from Northeast of Brazil. Methanolic, ethyl acetate and chloroform extracts from leaves of C. rupicola were evaluated in relation to their potential in inhibiting the cell growth and cytotoxic properties against nine human cancer cell lines (MCF-7, NCI-ADR/RES, OVCAR-3, PC-3, HT-29, NCIH460, 786-O, UACC-62, K-562). In addition, antioxidant activity of these extracts was measured using DPPH as radical scavenging assay and the ntimicrobial activities against nine pathogens were tested by agar diffusion method. Preliminary results showed that the this plant demonstrates to have moderate activity against bacteria but, on... |
| Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Combretum rupicola; Planta medicinal; Extrato vegetal; Plant extracts; Medicinal plants; Antioxidant activity; Antineoplastic agents. |
| Ano: 2013 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/950033 |
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| Chulaluck Charunuch; Plerncha Tangkanakul; Saovaluk Runggaeng. |
| Owing to creation of Thai rice snack with health benefits for higher potential in commercial scale, mulberry leaf was applied in the production of extruded snack product. Mulberry leaf in dried powder was mixed with rice, corn, soy, sugar, oil, vitamins and minerals to investigate the operating conditions with twin-screw extruder at varying mulberry content (5, 7.5 and 10%), screw speed (300 and 350 rpm) and feed moisture (13, 15 and 17%) in the 3 × 2 × 3 factorial experiment. The extrudates were examined of functional properties (antioxidant activity and phenolic compounds) and some physical characteristics (expansion ratio, bulk density, texture measurement and organoleptic test). The results had shown that at higher mulberry content (10%), the product... |
| Tipo: PhysicalObject |
Palavras-chave: Mulberry; Extruded snack; Antioxidant activity; Phenolic compounds; หม่อน; ฤทธิ์ต้านอนุมูลอิสระ; สารฟีโนลิก; เอ็กซ์ทรูดเดอร์; ผลิตภัณฑ์ขนมขบเคี้ยว; ผลิตภัณฑ์แปรรูปจากข้าว; คุณภาพทางประสาทสัมผัส. |
| Ano: 2006 |
URL: http://anchan.lib.ku.ac.th/agnet/handle/001/5256 |
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| Registros recuperados: 104 | |
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