title: Preparative isolation and purification of antioxidative stilbene oligomers from Vitis chunganeniss using high-speed counter-current chromatography in stepwise elution mode.
abstract: Preparative high-speed counter-current chromatography (HSCCC) was successfully applied to the isolation and purification of three stilbene oligomers from Vitis chunganeniss using stepwise elution with a pair of two-phase solvent systems composed of n-hexane-ethyl acetate-methanol-water at (2:5:2:5, v/v) and (1:2:1:2, v/v). The preparative HSCCC separation was performed on 800 mg of crude sample yielding hopeaphenol (21.1 mg), amurensin G (37.2 mg) and vitisin A (95.6 mg) in a one-step separation, with purities over 95% as determined by HPLC. The structures of these three compounds were identified by MS, (1)H NMR and (13)C NMR. In addition, their antioxidant activities were screened by DPPH assay, where vitisin A showed strong antioxidant activity. Further EPR experiments with spin-trapping technique demonstrated that vitisin A is a potent and selective singlet oxygen quencher, which may be used in singlet oxygen-mediated diseases as a pharmacological agent.
authors: Department of Chemistry, Zhejiang University, Hangzhou, China.
authors: Shan
authors: S
authors: He
authors: Yanbin
authors: Y
authors: Lu
authors: Liyan
authors: L
authors: Jiang
authors: Bin
authors: B
authors: Wu
authors: Feiying
authors: F
authors: Zhang
authors: Yuanjiang
authors: Y
authors: Pan
mesh_terms: D000085:Acetates / Q000737:chemistry; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D003377:Countercurrent Distribution / Q000295:instrumentation / Q000379:methods*; D006586:Hexanes / Q000737:chemistry; D000432:Methanol / Q000737:chemistry; D008968:Molecular Conformation; D012997:Solvents / Q000737:chemistry; D013267:Stilbenes / Q000737:chemistry / Q000302:isolation & purification*; D013997:Time Factors; D027843:Vitis / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D000085:Acetates; D000975:Antioxidants; D006586:Hexanes; D012997:Solvents; D013267:Stilbenes; D014867:Water; C026385:n-hexane; C007650:ethyl acetate; D000432:Methanol