title: Separation of betacyanins from purple flowers of Gomphrena globosa L. by ion-pair high-speed counter-current chromatography.
abstract: Betacyanins, known as antioxidants and chemopreventive natural compounds with colourful properties, were extracted from purple flowers of Gomphrena globosa L. belonging to the Amaranthaceae family and separated for the first time by ion-pair high-speed counter-current chromatography (HSCCC). The pigments were detected by LC-DAD-ESI-MS/MS technique. Separation of betacyanins (300mg) by HSCCC was accomplished in four solvent systems: tert-butyl methyl ether - butanol - acetonitrile - water (0.7% and 1.0% HFBA - heptafluorobutyric acid - system I and III) and tert-butyl methyl ether - butanol - methanol - water (0.7% and 1.0% HFBA - system II and IV) (2:2:1:5, v/v/v/v) in the head-to-tail mode. The mobile phase (aqueous phase) was run at 2.0ml/min and the column rotation speed was 860rpm. The applied systems enabled to study the influence of HFBA concentration as well as systems polarity on betacyanins separation. Comparison of the systems containing 0.7% HFBA (systems I-II) demonstrates that the replacement of acetonitrile by methanol increases the resolution (Rs) between all betacyanins and does not influence the retention of the stationary phase (Sf=76%). Higher concentration of the acid in systems III-IV slightly decreases Sfto 71% in the systems with 1.0% HFBA. Comparison of the resolution values for betacyanins in the systems with 0.7% and 1.0% HFBA demonstrates that higher concentration of the acid improves the separation effectiveness for all betacyanins as a result of increasing of the chemical affinity of the pigments to the organic stationary phase in HSCCC. The systems III-IV with 1% HFBA are the most effective for the separation of all the studied betacyanins.
authors.affiliation: Department of Analytical Chemistry, Institute C-1, Faculty of Chemical Engineering and Technology, Cracow University of Technology, ul. Warszawska 24, Cracow 31-155, Poland. Electronic address: anetasporna@chemia.pk.edu.pl.
authors.forename: Aneta
authors.initials: A
authors.lastname: Spórna-Kucab
authors.affiliation: Department of Analytical Chemistry, Institute C-1, Faculty of Chemical Engineering and Technology, Cracow University of Technology, ul. Warszawska 24, Cracow 31-155, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Jagodzińska
authors.affiliation: Department of Analytical Chemistry, Institute C-1, Faculty of Chemical Engineering and Technology, Cracow University of Technology, ul. Warszawska 24, Cracow 31-155, Poland.
authors.forename: Sławomir
authors.initials: S
authors.lastname: Wybraniec
mesh_terms: D027703:Amaranthaceae / Q000737:chemistry*; D050859:Betacyanins / Q000032:analysis / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution / Q000379:methods*; D035264:Flowers / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D053719:Tandem Mass Spectrometry
chemical_list: D050859:Betacyanins; D012997:Solvents
keywords: Betacyanins; Counter-current chromatography; Gomphrena globosa L.; Ion-pair reagents