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2-Styrylchromones: novel strong scavengers of reactive oxygen and nitrogen species IPB - Escola Superior Agrária
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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Anti-inflammatory potential of 2-styrylchromones regarding their interference with arachidonic acid metabolic pathways IPB - Escola Superior Agrária
Gomes, Ana; Fernandes, Eduarda; Silva, Artur; Pinto, Diana; Santos, Clementina M.M.; Cavaleiro, José; Lima, José Costa.
Cyclooxygenases (COXs) are the key enzymes in the biosynthesis of prostanoids. COX-1 is a constitutive enzyme while the expression of COX-2 is highly stimulated in the event of inflammatory processes, leading to the production of large amounts of prostaglandins (PGs), in particular PGE2 and PGI2, which are pro-inflammatory mediators. Lipoxygenases (LOXs) are enzymes that produce hydroxy acids and leukotrienes (LTs). 5-LOX metabolizes arachidonic acid to yield, among other products, LTB4, a potent chemoattractantmediator of inflammation. The aim of the present work was to evaluate the anti-inflammatory potential of 2-styrylchromones (2-SC), a chemical family of oxygen heterocyclic compounds, vinylogues of flavones (2-phenylchromones), by studying their...
Tipo: Article Palavras-chave: 2-Styrylchromones; Cyclooxygenase; 5-Lipoxigenase; Leukotriene B4; Dual inhibitors; Inflammation.
Ano: 2009 URL: http://hdl.handle.net/10198/3919
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Cyclic voltammetric analysis of 2-styrylchromones: Relationship with the antioxidant activity IPB - Escola Superior Agrária
Gomes, Ana; Fernandes, Eduarda; Garcia, M. Beatriz; Silva, Artur; Pinto, Diana; Santos, Clementina M.M.; Cavaleiro, José; Lima, José Costa.
2-Styrylchromones (2-SC) are a chemical family of oxygen heterocyclic compounds, vinylogues of flavones (2-phenylchromones), whose occurrence in nature has been reported. Recently, several 2-SC derivatives were demonstrated to have antioxidant properties, namely, xanthine oxidase inhibition, hepatoprotection against pro-oxidant agents in cellular and non-cellular systems and scavenging activity against reactive oxygen and reactive nitrogen species (ROS and RNS). Considering these antioxidant properties, it may be hypothesised that the electrochemical redox behaviour of 2-SC contributes significantly to their activity. To test this hypothesis, the electrochemical behaviour of different 2-SC was studied, together with a number of flavonoids with well-known...
Tipo: Article Palavras-chave: 2-Styrylchromones; Cyclic voltammetry; Oxidation mechanism; Scavenging activity; Reactive oxygen species; Reactive nitrogen species.
Ano: 2008 URL: http://hdl.handle.net/10198/4011
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Epoxidation studies of 2-styrylchromones using Jacobsen’s catalyst and hydrogen peroxide and iodosylbenzene as oxidants IPB - Escola Superior Agrária
Santos, Clementina M.M.; Silva, Artur; Cavaleiro, José; Patonay, Támas; Lévai, Albert.
The epoxidation of 2-styrylchromones 2a-h using Jacobsen’s Mn(III)[salen] complex 1 as catalyst is reported for the first time. Several studies were performed using both hydrogen peroxide and iodosylbenzene as oxidants, in order to obtain the α,β-epoxy-2-styrylchromones 3a-h regioselectively. Due to the low reactivity of the substrates and the highly unstable character of the formed epoxides, reactions should be interrupted at lower conversions to obtain acceptable yields, especially when hydrogen peroxide is used.
Tipo: Article Palavras-chave: 2-Styrylchromones; Jacobsen catalyst; Epoxidation; Iodosylbenzene; Hydrogen peroxide.
Ano: 2006 URL: http://hdl.handle.net/10198/3923
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Hepatoprotective activity of polyhydroxylated 2-styrylchromones against tert-butylhydroperoxide induced toxicity in freshly isolated rat hepatocytes IPB - Escola Superior Agrária
Fernandes, Eduarda; Carvalho, M.; Carvalho, Félix; Silva, Artur; Santos, Clementina M.M.; Pinto, Diana; Cavaleiro, José; Bastos, Maria de Lourdes.
2-Styrylchromones are a novel class of chromones, vinylogues of flavones (2-phenylchromones), which have recently been found in nature. The best described property of almost every group of flavones and other flavonoids, especially the hydroxylated derivatives, is their capacity to act as antioxidants. Indeed there is a widely accepted view that the positive health effects of flavones are due to their antioxidant activity. As oxidative stress is a main cause of liver toxicity induced by several hepatotoxicants, agents with the ability to protect the liver against reactive pro-oxidant species may be therapeutically useful. The present study evaluated the possible protective activity of six new synthetic polyhydroxylated 2-styrylchromone derivatives against...
Tipo: Article Palavras-chave: 2-Styrylchromones; Tert-Butylhydroperoxide; Hepatoprotective activity; Freshly isolated rat hepatocytes.
Ano: 2003 URL: http://hdl.handle.net/10198/3977
Registros recuperados: 5
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