title: Antioxidant flavonoids from Epimedium wushanense.
abstract: Two new flavonoids, wushanicaritin (1) and wushankaempferol (2), along with 24 known flavonoids were isolated from the whole herb of Epimedium wushanense T.S. Ying (Berberidaceae). On the basis of NMR and ESI-MS spectroscopic analysis, structures of compounds 1 and 2 were elucidated as 8-γ-hydroxy-γ,γ-dimethylpropyl-3,5,7-trihydroxy-4'- methoxyflavone and kaempferol 3-O-α-l-[2,3-di-O-β-D-(6-E-p-coumaroyl) glucopyranosyl]-rhamnopyranosyl-7-O-α-L-rhamnopyranoside, respectively. DPPH radical scavenging activity tests indicated that 1 (IC(50) 35.3 μM) exhibited antioxidant activity comparable to Vitamin C (IC(50) 32.0 μM), while 2 (IC(50) 443.7 μM) showed weak activity.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
authors.forename: Hui-fang
authors.initials: HF
authors.lastname: Li
authors.forename: Xiang-yu
authors.initials: XY
authors.lastname: Guan
authors.forename: Wen-zhi
authors.initials: WZ
authors.lastname: Yang
authors.forename: Ke-di
authors.initials: KD
authors.lastname: Liu
authors.forename: Min
authors.initials: M
authors.lastname: Ye
authors.forename: Chao
authors.initials: C
authors.lastname: Sun
authors.forename: Shuang
authors.initials: S
authors.lastname: Lu
authors.forename: De-an
authors.initials: DA
authors.lastname: Guo
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D034181:Epimedium / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry* / Q000494:pharmacology*; D015394:Molecular Structure
chemical_list: D000975:Antioxidants; D005419:Flavonoids; C571373:wushanicaritin; C571372:wushankaempferol