Abstract
From the methylene chloride extract of the leaves of Guiera senegalensis a novel naphthopyran, 5-methylflavasperone (5,8,10-trimethoxy-2-methyl-4 H-naphtho[1,2-b]pyran-4-one), as well as rhamnetin were isolated. Rhamnetin showed a strong inhibitory activity on 5-lipoxygenase from porcine leucocytes with an IC50 value of 0.7 microM whereas 5-methylflavasperone revealed only a weak inhibitory activity (IC50 > 200 microM). In the deoxyribose assay both compounds exerted similar antiradicalar effects (IC50 15.8 and 16.7 microM, respectively). In another assay only rhamnetin inhibited peroxidation of phospholipid liposomes (IC50 = 2.4 microM). For 5-methylflavasperone no dose dependent inhibition could be observed.
MeSH terms
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Animals
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Antioxidants / isolation & purification*
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Antioxidants / pharmacology
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Chromones / isolation & purification*
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Chromones / pharmacology
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Cyclooxygenase 1
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Cyclooxygenase Inhibitors / isolation & purification
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Cyclooxygenase Inhibitors / pharmacology
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Hydroxyeicosatetraenoic Acids / antagonists & inhibitors
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In Vitro Techniques
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Isoenzymes / metabolism
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Leukocytes / drug effects
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Leukocytes / enzymology
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Leukotriene B4 / antagonists & inhibitors
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Liposomes
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Lipoxygenase Inhibitors* / isolation & purification*
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Lipoxygenase Inhibitors* / pharmacology
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Magnetic Resonance Spectroscopy
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Plant Leaves / chemistry
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Plants, Medicinal / chemistry*
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Prostaglandin-Endoperoxide Synthases / metabolism
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Quercetin / analogs & derivatives*
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Quercetin / isolation & purification
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Quercetin / pharmacology
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Swine
Substances
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5-methylflavasperone
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Antioxidants
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Chromones
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Cyclooxygenase Inhibitors
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Hydroxyeicosatetraenoic Acids
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Isoenzymes
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Liposomes
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Lipoxygenase Inhibitors
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Leukotriene B4
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5-hydroxy-6,8,11,14-eicosatetraenoic acid
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rhamnetin
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Quercetin
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Cyclooxygenase 1
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Prostaglandin-Endoperoxide Synthases