title: Quick preparative separation of natural naphthopyranones with antioxidant activity by high-speed counter-current chromatography.
abstract: The natural naphthopyranones paepalantine [structure: see text], paepalantine-9-O-beta-D-glucopyranoside [structure: see text] and paepalantine-9-O-beta-D-allopyranosyl-(1-->6)-O-beta-D-glucopyranoside [structure: see text] were separated in a preparative scale from the ethanolic extract of the capitula of Paepalanthus bromelioides by high-speed counter-current chromatography (HSCCC). The solvent system used was composed of water-ethanol-ethyl acetate-hexane (10:4:10:4, v/v/v/v). This technique led to the separation of the three different naphthopyranone glycosides in pure form in approximately 7 hours. Paepalantine showed a good antioxidant activity when assayed by the DPPH radical spectrophotometric assay.
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais, UFRJ, Rio de Janeiro, RJ, Brazil.
authors.forename: Gilda G
authors.initials: GG
authors.lastname: Leitão
authors.forename: Suzana G
authors.initials: SG
authors.lastname: Leitão
authors.forename: Wagner
authors.initials: W
authors.lastname: Vilegas
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification* / Q000494:pharmacology; D001938:Brazil; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003377:Countercurrent Distribution / Q000379:methods; D039262:Eriocaulaceae / Q000737:chemistry; D000431:Ethanol; D005609:Free Radicals; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D006575:Heterocyclic Compounds, 3-Ring / Q000302:isolation & purification*; D009281:Naphthalenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D011753:Pyrones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D006027:Glycosides; D006575:Heterocyclic Compounds, 3-Ring; D009281:Naphthalenes; D010936:Plant Extracts; D011753:Pyrones; D000431:Ethanol