title: Antioxidant and free-radical scavenging activity of constituents of the leaves of Tachigalia paniculata.
abstract: Two new myricetin glycosides, myricetin 7-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside (1) and myricetin 7-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (2), together with the known compounds quercetin 3-O-beta-D-glucopyranoside (3), quercetin 3-O-alpha-L-rhamnopyranoside (4), quercetin 3-O-beta-D-galactopyranoside (5), methyl gallate (6), isovanillin (7), 4-hydroxymethylbenzoate (8), 3,4-dihydroxymethylbenzoate (9), and caffeoyl aldehyde (10) were isolated from the leaves of Tachigalia paniculata. The structures of these compounds were determined by spectroscopic methods. Their antioxidant activity was determined by measuring free-radical scavenging effects using three different assays, namely, the Trolox Equivalent Antioxidant Capacity (TEAC) assay, the coupled oxidation of beta-carotene and linoleic acid (autoxidation assay), and the inhibition of xanthine oxidase activity. Compounds 1, 2, and 6 showed activity in the TEAC test, compounds 5-7 and 10 were moderately active in the autoxidation assay, while compounds 1 and 2 were the most potent of the isolates in the xanthine oxidase test.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università di Salerno, Via Ponte Don Melillo, 84084 Fisciano (SA), Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Cioffi
authors.forename: Marta
authors.initials: M
authors.lastname: D'Auria
authors.forename: Alessandra
authors.initials: A
authors.lastname: Braca
authors.forename: Jeannette
authors.initials: J
authors.lastname: Mendez
authors.forename: Anibal
authors.initials: A
authors.lastname: Castillo
authors.forename: Ivano
authors.initials: I
authors.lastname: Morelli
authors.forename: Francesco
authors.initials: F
authors.lastname: De Simone
authors.forename: Nunziatina
authors.initials: N
authors.lastname: De Tommasi
mesh_terms: D000465:Algorithms; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D007887:Fabaceae / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D013237:Stereoisomerism; D014687:Venezuela; D014969:Xanthine Oxidase / Q000378:metabolism; D019207:beta Carotene / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D016166:Free Radical Scavengers; D006027:Glycosides; C471273:myricetin 7-O-glucopyranosyl-(1-6)-glucopyranoside; C471274:myricetin 7-O-rhamnopyranosyl-(1-6)-glucopyranoside; D019207:beta Carotene; D014969:Xanthine Oxidase