title: Preparative separation of isoflavone components in soybeans using high-speed counter-current chromatography.
abstract: Four isoflavone components were purified from soybean extract by high-speed counter-current chromatography (HSCCC). Two types of multilayer coil separation columns were used: a small column made of standard 2.6-mm I.D. PTFE (polytetrafluoroethylene) tubing with a 260-ml capacity and a large column of convoluted PTFE tubing of 5.7-mm average I.D. with a 1,200-ml capacity. Separation was performed with a two-phase solvent system composed of hexane-ethyl acetate-1-butanol-methanol-acetic acid-water (1:2:1:1:5:1, v/v) by eluting the lower aqueous phase at 2 ml/min (small column) and 5 ml/min (large column) at a revolution speed of 700 rpm. From 500 mg of crude sample the small column yielded 33 mg of daidzin, 41 mg of genistin, 27 mg of 6''-O-malonyldaidzin and 24 mg of 6"-O-malonylgenistin. The large convoluted column separated, from 3 g of crude sample, 203 mg of daidzin, 241 mg of genistin, 158 mg of 6''-Omalonyldaidzin and 135 mg of 6"-O-malonylgenistin all at over 90% purity. The convoluted tubing facilitated preparation of a large multilayer coil due to its high flexibility.
authors.affiliation: Institute of Food and Biological Engineering, Hangzhou University of Commerce, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Du
authors.forename: Z
authors.initials: Z
authors.lastname: Lib
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
mesh_terms: D002845:Chromatography / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D007529:Isoflavones / Q000302:isolation & purification*; D013025:Glycine max / Q000737:chemistry*
chemical_list: D007529:Isoflavones