title: Antioxidant constituents of Caragana tibetica.
abstract: Caragana tibetica KOM. (Fabaceae) is a medicinal plant that has been traditionally used in western part of China. In the course of our screening study on antioxidant activity of medicinal plants, the 70% acetone extract of the stems of C. tibetica was found to have a potent superoxide anion scavenging activity. Tibeticanol (1), a new piceatannol dimer possessing antioxidant activity, was isolated along with eleven known aromatic compounds. Their structures were elucidated on the basis of NMR and MS data. Enzyme oxidation of monomeric stilbene, piceatannol (3), with horseradish peroxidase and hydrogen peroxide yielded cassigarol E (5) and G (6) as major products. Most of the isolated compounds exhibited superoxide anion scavenging activity.
authors.affiliation: Toyama International Research Center for Traditional Medicine; 151 Tomosugi, Toyama 939-8224, Japan.
authors.forename: Ting
authors.initials: T
authors.lastname: Xiang
authors.forename: Toshio
authors.initials: T
authors.lastname: Uno
authors.forename: Fumino
authors.initials: F
authors.lastname: Ogino
authors.forename: Cuoqian
authors.initials: C
authors.lastname: Ai
authors.forename: Jie
authors.initials: J
authors.lastname: Duo
authors.forename: Ushio
authors.initials: U
authors.lastname: Sankawa
mesh_terms: D000107:Acetylation; D000975:Antioxidants / Q000737:chemistry*; D032602:Caragana / Q000737:chemistry*; D002236:Carbohydrate Conformation; D016166:Free Radical Scavengers / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D018547:Plant Stems / Q000737:chemistry; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013267:Stilbenes / Q000737:chemistry; D013481:Superoxides / Q000737:chemistry
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D013267:Stilbenes; C505046:tibeticanol; D013481:Superoxides; C041525:3,3',4,5'-tetrahydroxystilbene; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase