title: Centrifugal partition chromatography applied to the isolation of oak wood aroma precursors.
abstract: Flavours extracted from oak wood during barrel ageing contribute to the organoleptic character of wines and spirits. The aim of this work was to identify the glycosidic precursors of the key volatile compounds responsible for oak wood aroma. Oak extract is a very complex matrix and, furthermore, precursors are present in very small quantities. Preparative centrifugal partition chromatography (CPC) is a promising solution for purifying the oak extract. The solvent system was selected on the basis of the partition coefficient of glycosidase enzyme activity (Kca). Thanks to the efficacy of CPC separation, three glucoside gallates were subsequently isolated by HPLC chromatography. Vanillin-(6'-O-galloyl)-O-β-D-glucopyranoside, 3,4,5-trimethoxyphenyl-(6'-O-galloyl)-O-β-D-glucopyranoside, and (6R,9R)-3-oxo-α-ionol-9-O-(6'-O-galloyl)-β-glucopyranoside (macarangioside E) were isolated and identified. This was the first time that vanillin-(6'-O-galloyl)-O-β-D-glucopyranoside was identified and the first time that macarangioside E was isolated from oak wood. Heating macarangioside E resulted in the formation of megastigmatrienone, which has an aroma reminiscent of tobacco.
authors.affiliation: Univ. de Bordeaux, ISVV, EA 4577, Unité de Recherche Œnologie, 33882 Villenave d'Ornon, France.
authors.forename: Davide
authors.initials: D
authors.lastname: Slaghenaufi
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Marchand-Marion
authors.forename: Tristan
authors.initials: T
authors.lastname: Richard
authors.forename: Pierre
authors.initials: P
authors.lastname: Waffo-Teguo
authors.forename: Jonathan
authors.initials: J
authors.lastname: Bisson
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Monti
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Merillon
authors.forename: Gilles
authors.initials: G
authors.lastname: de Revel
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005421:Flavoring Agents / Q000032:analysis / Q000302:isolation & purification; D006027:Glycosides / Q000032:analysis / Q000302:isolation & purification*; D029963:Quercus / Q000737:chemistry*; D055549:Volatile Organic Compounds / Q000032:analysis / Q000302:isolation & purification*; D014934:Wood / Q000737:chemistry*
chemical_list: D005421:Flavoring Agents; D006027:Glycosides; D055549:Volatile Organic Compounds
keywords: 3,4,5-Trimethoxyphenyl; 3-Oxo-α-ionol; Centrifugal partition chromatography; Glucoside gallate precursors; Oak wood; Vanillin