title: Centrifugal partition extraction in the pH-zone-refining displacement mode: an efficient strategy for the screening and isolation of biologically active phenolic compounds.
abstract: Centrifugal partition extraction (CPE) was developed for the first time in the pH-zone-refining mode to fractionate a crude bark extract of the African tree Anogeissus leiocarpus Guill. & Perr. (Combretaceae). The fractionation process was performed at a flow rate of 20mL/min using a biphasic solvent system composed of methyl tert-butyl ether/acetonitrile/water (4:1:5, v/v/v) in the ascending mode. Sodium hydroxide (40mM) and trifluoroacetic acid (30mM) were used as retainer and displacer agents, respectively. In a single run of 67min, 3g of the initial crude extract were successfully separated into fractions selectively enriched in ionizable triterpenes, ellagic acid derivatives and flavonoids. The antioxidant potential of the initial crude extract, isolated compounds and fraction pools was also evaluated by using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) stable free radical scavenging assay, providing an interesting view about the effect of the degree of substitution of ellagic acid derivatives on their radical scavenging activity. This study will demonstrate that centrifugal partition extraction used in the pH-zone-refining mode can be proposed as an efficient strategy for the rapid screening of natural phenolic compounds.
authors.affiliation: UMR CNRS 7312, Université de Reims Champagne-Ardenne, Bât. 18, Moulin de la Housse, BP 1039, 51687 Reims, Cedex 2, France.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Hamzaoui
authors.forename: Jean-Hugues
authors.initials: JH
authors.lastname: Renault
authors.forename: Romain
authors.initials: R
authors.lastname: Reynaud
authors.forename: Jane
authors.initials: J
authors.lastname: Hubert
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D001713:Biphenyl Compounds / Q000032:analysis / Q000378:metabolism; D002498:Centrifugation / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods; D029764:Combretaceae / Q000737:chemistry; D004610:Ellagic Acid; D005419:Flavonoids; D006863:Hydrogen-Ion Concentration; D019906:Nuclear Magnetic Resonance, Biomolecular; D010636:Phenols / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D010851:Picrates / Q000032:analysis / Q000378:metabolism; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D014315:Triterpenes
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D005419:Flavonoids; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D014315:Triterpenes; D004610:Ellagic Acid; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Anogeissus leiocarpus; Centrifugal partition chromatography; Centrifugal partition extraction; DPPH; Ellagic acid; pH-zone-refining