title: Separation and Purification of Ombuoside from Gynostemma Pentaphyllum by Microwave-Assisted Extraction Coupled with High-Speed Counter-current Chromatography.
abstract: A rapid and efficient method for the separation and purification of ombuoside from Gynostemma pentaphyllum by microwave-assisted extraction coupled with high-speed counter-current chromatography (HSCCC) was successfully developed. Using an orthogonal array design L9(34), the extraction conditions, including microwave power, irradiation time, solid-to-liquid ratio and extraction times, were optimized. Ombuoside was isolated and purified from the crude extraction by HSCCC with two-phase solvent system composed of n-hexane:ethyl acetate:ethanol:water (5:6:5:5, v/v) in a single run. A 210 mg quantity of the crude extract containing 2.16% ombuoside was loaded, yielding 3.9 mg of ombuoside at 96.7% purity. The chemical structure of ombuoside was determined by comparison with the high-performance liquid chromatography retention time of standard substance as well as UV, FT-IR, ESI-MS,1H NMR and13C NMR spectra. The purified ombuoside had strong 1,1-diphenyl-2-picrylhydrazyl and hydroxyl free radical scavenging activities.
authors.affiliation: College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109, P.R. China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Jiang
authors.affiliation: College of Animal Science and Technology, Qingdao Agricultural University, Qingdao 266109, P.R. China.
authors.forename: Hu
authors.initials: H
authors.lastname: Shan
authors.affiliation: College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109, P.R. China.
authors.forename: Jiying
authors.initials: J
authors.lastname: Song
authors.affiliation: College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109, P.R. China htlu6@sina.com.
authors.forename: Haitao
authors.initials: H
authors.lastname: Lü
mesh_terms: D000975:Antioxidants; D005591:Chemical Fractionation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution / Q000379:methods; D005419:Flavonoids / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D029774:Gynostemma / Q000737:chemistry*; D008872:Microwaves; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010936:Plant Extracts; C062974:ombuoside