Structures of enzymically derived oligosaccharides from sorghum glucuronoarabinoxylan.
Oligosaccharides derived from alkali-extracted sorghum glucuronoarabinoxylan by digestion with a combination of (1-->4)-beta-D-arabinoxylan arabinofuranohydrolase (AXH) and endo-(1-->4)-beta-D-xylanase (Xyl I), both from Aspergillus awamori, were purified by size-exclusion chromatography followed by preparative high-performance anion-exchange chromatography. Structural studies including monosaccharide analysis, methylation analysis, 1H NMR spectroscopy, and mass spectrometry were carried out, resulting in the characterisation of four novel oligosaccharides, namely, alpha-D-GlcpA-(1-->2)-beta-D-Xyl p-(1-->4)-beta-D-Xyl p-(1-->4) -beta-D-Xyl p, alpha-D-GlcpA-(1-->2)-beta-D-Xyl p-(1-->4) [alpha-L-Araf-(1-->3)]-beta-D-Xyl p-(1-->4)-beta-D-Xyl p, alpha-D-GlcpA-(1-->2)-beta-D- Xyl p-(1-->4)-beta-D-Xyl p-(1-->4)[alpha-L-Araf-(1-->2)-alpha)-alpha- L-Araf-(1-->3)]-beta-D-Xyl p-(1-->4)-beta-D-Xyl p, and alpha-D-GlcpA-(1-->2) -beta-D-Xyl p-(1-->4)[alpha-L-Araf-(1-->3] beta-D-Xyl p-(1-->4)[alpha-L-Araf-(1-->2)-alpha-L-Araf-(1-->3)] -beta-D-Xyl p-(1-->4)-beta-D-Xyl p. The various oligosaccharides identified provide additional insight into the structure of sorghum glucuronoarabinoxylan. Furthermore, novel data were generated with respect to the substrate specificity of AXH and Xyl I towards glucuronoarabinoxylans in general.
Wageningen Agricultural University, Department of Food Science, Netherlands.
M A
MA
Verbruggen
B A
BA
Spronk
H A
HA
Schols
G
G
Beldman
A G
AG
Voragen
J R
JR
Thomas
J P
JP
Kamerling
J F
JF
Vliegenthart
D001230:Aspergillus / Q000201:enzymology; D002240:Carbohydrate Sequence; D002523:Edible Grain / Q000737:chemistry*; D043364:Endo-1,4-beta Xylanases; D005656:Fungal Proteins / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013379:Substrate Specificity; D014990:Xylans / Q000737:chemistry* / Q000302:isolation & purification; D014995:Xylosidases / Q000378:metabolism*
D005656:Fungal Proteins; D009844:Oligosaccharides; D014990:Xylans; C114470:glucuronoarabinoxylan; D006026:Glycoside Hydrolases; D014995:Xylosidases; C019713:alpha-N-arabinofuranosidase; D043364:Endo-1,4-beta Xylanases