title: Antioxidant secondary metabolites from Geranium lasiopus Boiss. & Heldr.
abstract: Chromatographic studies on the EtOAc soluble portion of the MeOH extract of Geranium lasiopus led to the isolation of eight flavonoids (kaempferol (1), quercetin (2), quercetin 3-O-β-glucopyranoside (3), quercetin 3-O-β-galactopyranoside (4), kaempferol 3-O-α-rhamnopyranosyl-(1 → 6)-β-glucopyranoside (5), quercetin 3-O-α-rhamnopyranosyl-(1 → 6)-β-glucopyranoside (6), kaempferol 3-O-α-rhamnopyranosyl-(1 → 2)-β-glucopyranoside (7) and quercetin 3-O-α-rhamnopyranosyl-(1 → 2)-β-glucopyranoside (8)), two simple phenolic compounds (gallic acid (9) and its methyl ester (10)) and a hydrolysable tannin (pusilagin (11)). The structures of the compounds were elucidated by 1- and 2-dimensional NMR techniques ((1)H, (13)C, COSY, HMBC, HMQC) and ESI-TOF-MS spectrometry. Inhibitory effects on H(2)O(2)-induced lipid peroxidation in human red blood cells of the different extracts of G. lasiopus, as well as isolated compounds, were investigated. All tested compounds showed comparable or higher activity than that of ascorbic acid and trolox.
authors: Department of Pharmacognosy, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey. didems@hacettepe.edu.tr
authors: Didem
authors: D
authors: Söhretoğlu
authors: Mahmut Koray
authors: MK
authors: Sakar
authors: Suna Atasayar
authors: SA
authors: Sabuncuoğlu
authors: Hilal
authors: H
authors: Ozgüneş
authors: Hayri
authors: H
authors: Duman
authors: Olov
authors: O
authors: Sterner
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology; D031315:Geranium / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D021241:Spectrometry, Mass, Electrospray Ionization; D013634:Tannins / Q000737:chemistry
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010936:Plant Extracts; D013634:Tannins; D006861:Hydrogen Peroxide