Location of O-acetyl substituents in xylo-oligosaccharides obtained from hydrothermally treated Eucalyptus wood.
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.
Kabel
Mirjam A
MA
Department of Agrotechnology and Food Sciences, Laboratory of Food Chemistry, Wageningen University, Bomenweg 2, 6703 HD, Wageningen, The Netherlands.
de Waard
Pieter
P
Schols
Henk A
HA
Voragen
Alphons G J
AG
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*
D009844:Oligosaccharides; D014994:Xylose