title: 5-Methylflavasperone and rhamnetin from Guiera senegalensis and their antioxidative and 5-lipoxygenase inhibitory activity.
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.
authors.affiliation: Institute of Pharmacognosy, University of Graz, Austria.
authors.forename: F
authors.initials: F
authors.lastname: Bucar
authors.forename: M
authors.initials: M
authors.lastname: Resch
authors.forename: R
authors.initials: R
authors.lastname: Bauer
authors.forename: M
authors.initials: M
authors.lastname: Burits
authors.forename: E
authors.initials: E
authors.lastname: Knauder
authors.forename: M
authors.initials: M
authors.lastname: Schubert-Zsilavecz
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000302:isolation & purification* / Q000494:pharmacology; D002867:Chromones / Q000302:isolation & purification* / Q000494:pharmacology; D051545:Cyclooxygenase 1; D016861:Cyclooxygenase Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D006893:Hydroxyeicosatetraenoic Acids / Q000037:antagonists & inhibitors; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000378:metabolism; D007962:Leukocytes / Q000187:drug effects / Q000201:enzymology; D007975:Leukotriene B4 / Q000037:antagonists & inhibitors; D008081:Liposomes; D016859:Lipoxygenase Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011794:Quercetin / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000494:pharmacology; D013552:Swine
chemical_list: C118041:5-methylflavasperone; D000975:Antioxidants; D002867:Chromones; D016861:Cyclooxygenase Inhibitors; D006893:Hydroxyeicosatetraenoic Acids; D007527:Isoenzymes; D008081:Liposomes; D016859:Lipoxygenase Inhibitors; D007975:Leukotriene B4; C022022:5-hydroxy-6,8,11,14-eicosatetraenoic acid; C063423:rhamnetin; D011794:Quercetin; D051545:Cyclooxygenase 1; D011451:Prostaglandin-Endoperoxide Synthases