title: Phenolic antioxidant scavenging of myosin radicals generated by hypervalent myoglobin.
abstract: The scavenging activity of extracts of green tea (GTE), white grape (WGE), and rosemary (RE), all plant material with high phenolic content, and of the phenolic compounds 4-methylcatechol (4-MC), (+)-catechin, and carnosic acid toward long-lived myosin radicals generated by reaction with H2O2-activated myoglobin at room temperature (pH 7.5, I=1.0) was investigated by freeze-quench ESR spectroscopy. Myosin radicals were generated by incubating 16 μM myosin, 800 μM metmyoglobin, and 800 μM H2O2 for 10 min, and the phenolic extracts were subsequently added (1% (w/w) phenolic compounds relative to myosin). GTE was able to scavenge myosin radicals and reduce the radical intensity by 65%. Furthermore, a low concentration of 4-MC (33 μM) was found to increase the radical concentration when added to the myosin radicals, whereas a higher concentration of 4-MC and catechin (330 μM) was found to scavenge myosin radicals and reduce the overall radical concentration by ∼65%.
authors.affiliation: Food Chemistry, Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
authors.forename: Sisse
authors.initials: S
authors.lastname: Jongberg
authors.forename: Marianne N
authors.initials: MN
authors.lastname: Lund
authors.forename: Henrik
authors.initials: H
authors.lastname: Østdal
authors.forename: Leif H
authors.initials: LH
authors.lastname: Skibsted
mesh_terms: D045784:Abietanes / Q000737:chemistry; D000975:Antioxidants / Q000737:chemistry*; D002392:Catechin / Q000737:chemistry / Q000494:pharmacology; D002396:Catechols / Q000737:chemistry / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000494:pharmacology; D006735:Horseradish Peroxidase / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D008786:Metmyoglobin / Q000737:chemistry; D009211:Myoglobin / Q000737:chemistry*; D009218:Myosins / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D027542:Rosmarinus / Q000737:chemistry; D013662:Tea / Q000737:chemistry; D027843:Vitis / Q000737:chemistry
chemical_list: D045784:Abietanes; D000975:Antioxidants; D002396:Catechols; D016166:Free Radical Scavengers; D009211:Myoglobin; D010636:Phenols; D010936:Plant Extracts; D013662:Tea; D008786:Metmyoglobin; C018599:4-methylcatechol; D002392:Catechin; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D009218:Myosins; C018381:salvin