title: Location of O-acetyl substituents in xylo-oligosaccharides obtained from hydrothermally treated Eucalyptus wood.
abstract: A combination of techniques was used to localise the O-acetyl substituents in xylo-oligosaccharides, which are present in hydrolysates of hydrothermally treated Eucalyptus wood. Reversed-phase (RP)-high performance liquid chromatography (HPLC) coupled on-line to both a mass spectrometer and an evaporating light scattering (ELS) detector provided data about the order of elution of the various O-acetylated oligomers. The retention of the oligomers on the column depended on the number and position of the O-acetyl substituents within the xylo-oligosaccharides. One dimensional (1D)- and two dimensional (2D)-(1)H NMR spectroscopy was used to study the structural features of several xylotetramers separated by RP-HPLC, each having one O-acetyl substituent. O-Acetyl migration was proven to have occurred in these xylo-oligosaccharides. Mainly O-acetyl migration within the same xylosyl residue was observed. RP-HPLC-NMR was performed in order to study the structural features of the acetylated oligomers 'on-line' avoiding O-acetyl migration. Finally, the precise location of the 2-O- or 3-O-acetyl substituent in 6 xylotetramers and 4 xylotrimers separated by RP-HPLC was determined.
authors.affiliation: Department of Agrotechnology and Food Sciences, Laboratory of Food Chemistry, Wageningen University, Bomenweg 2, 6703 HD, Wageningen, The Netherlands.
authors.forename: Mirjam A
authors.initials: MA
authors.lastname: Kabel
authors.forename: Pieter
authors.initials: P
authors.lastname: de Waard
authors.forename: Henk A
authors.initials: HA
authors.lastname: Schols
authors.forename: Alphons G J
authors.initials: AG
authors.lastname: Voragen
mesh_terms: D000107:Acetylation; D002851:Chromatography, High Pressure Liquid; D005052:Eucalyptus / Q000737:chemistry*; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D014934:Wood; D014994:Xylose / Q000737:chemistry*
chemical_list: D009844:Oligosaccharides; D014994:Xylose