Large-scale isolation of flavan-3-ol phloroglucinol adducts by high-speed counter-current chromatography.
Flavan-3-ol phloroglucinol adducts were synthesised through acid catalysed degradation of a procyanidins-rich grape seed extract in the presence of phloroglucinol. The reaction mixture (3.3 g) was fractionated without further sample preparation using the all-liquid chromatographic technique of high-speed counter-current chromatography (HSCCC). Selected solvent systems were hexane-ethyl acetate-methanol-water (0.1:5:0.1:5, v/v/v/v) and (1.5:10:1.5:10, v/v/v/v). The fractions obtained were found to contain almost pure compounds, in some cases final purification was achieved by preparative HPLC. The so-obtained pure standards of (+)catechin-(4alpha-->2)-phloroglucinol, (-)epicatechin-(4beta-->2)-phloroglucinol, (+)catechine, (-)epicatechin-3-O-galloyl-(4beta-->2)-phloroglucinol, (-)epicatechin, and (-)epicatechin gallate are required for quantification of acid-catalysed phloroglucinol degradation products of procyanidins.
Köhler
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Institute of Food Chemistry, Technical University of Braunschweig, Schleinitzstr. 20, Braunschweig, Germany.
Winterhalter
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D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution / Q000379:methods*; D005419:Flavonoids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010696:Phloroglucinol / Q000302:isolation & purification*
D005419:Flavonoids; C404987:flavan-3-ol; D010696:Phloroglucinol