title: C-glycosyl flavones from Peperomia blanda.
abstract: The methanol extract from aerial parts of the Peperomia blanda (Piperaceae) yielded two C-glycosyl-flavones. Their structures were elucidated on the basis of extensive spectroscopic analysis, including 1D and 2D NMR, chemical transformation and comparison with the related known compounds. The structure of the new flavonoids were established as 4'-methoxy-vitexin 7-O-beta-D-xylopyranoside (1) (7-O-beta-D-xylopyranosyl-8-C-beta-D-glucopyranosyl-4'-methoxy-apigenin) and vicenin-2 (2). The antioxidant activity of both compounds was investigated using the DPPH assay. Both compounds showed only modest activity, with IC50 values of 357.2 microM for 1, and 90.5 microM for 2.
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, 21941-590, Rio de Janeiro, Brazil.
authors.forename: Leosvaldo S M
authors.initials: LS
authors.lastname: Velozo
authors.forename: Marcelo J P
authors.initials: MJ
authors.lastname: Ferreira
authors.forename: Maria Isabel S
authors.initials: MI
authors.lastname: Santos
authors.forename: Davyson L
authors.initials: DL
authors.lastname: Moreira
authors.forename: Elsie F
authors.initials: EF
authors.lastname: Guimarães
authors.forename: Vicente P
authors.initials: VP
authors.lastname: Emerenciano
authors.forename: Maria Auxiliadora C
authors.initials: MA
authors.lastname: Kaplan
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D047310:Apigenin / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D005960:Glucosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D015394:Molecular Structure; D036941:Peperomia / Q000737:chemistry*; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology
chemical_list: C540039:4'-methoxy-vitexin 7-O-beta-D-xylopyranoside; D000975:Antioxidants; D047309:Flavones; D005960:Glucosides; D010936:Plant Extracts; C530449:apigenin-6,8-di-C-glycopyranoside; D047310:Apigenin