title: Effective two-dimensional counter-current chromatographic method for simultaneous isolation and purification of oridonin and ponicidin from the crude extract of Rabdosia rubescens.
abstract: A preparative two-dimensional counter-current chromatographic system (2D-CCC) for simultaneous separation and purification of oridonin and ponicidin from the crude extract of Rabdosia rubescens was presented. It was based on the use of a high-speed CCC (HSCCC, total column volume V(c)=146ml) instrument in the first dimension (1st-D) and a preparative upright CCC (UCCC, V(c)=1500ml) column in the second dimension (2nd-D). The interface was a homemade column-switching system with a 50-ml sample loop. In this way, almost the whole interested region from the first dimension was transferred on-line to the second dimension for further separation. The use of a pair of two-phase solvent systems composed of n-hexane-ethyl acetate-methanol-water (1:5:1:5 and 3:5:3:5, v/v) in the two dimensions permitted the simultaneous separation of oridonin and ponicidin, making this 2D-CCC system with satisfactory resolution and peak capacity. During about 9h separation, two injections with about a 250mg amount of the crude extract for each, was accomplished using this 2D-CCC system, yielding 60mg of oridonin (1) and 10mg of ponicidin (2) all at a purity of over 95% as determined by HPLC analysis. Their chemical structures were identified by electrospray ionization (ESI) MS, (1)H NMR and (13)C NMR.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Lu
authors.forename: Cuirong
authors.initials: C
authors.lastname: Sun
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.forename: Yuanjiang
authors.initials: Y
authors.lastname: Pan
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution / Q000295:instrumentation / Q000379:methods*; D004224:Diterpenes / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D045786:Diterpenes, Kaurane / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D037602:Isodon / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D004224:Diterpenes; D045786:Diterpenes, Kaurane; D010936:Plant Extracts; C011959:oridonin; C090365:ponicidin