1H-N.m.r. study of enzymically generated wheat-endosperm arabinoxylan oligosaccharides: structures of hepta- to tetradeca-saccharides containing two or three branched xylose residues.
The structures of hepta- to tetradeca-saccharides, generated by digestion of wheat-endosperm arabinoxylan with endo-(1----4)-beta-D-xylanase, and isolated by gel-permeation chromatography on Bio-Gel P-6 and high-performance anion-exchange chromatography with pulsed amperometric detection (h.p.a.e.-p.a.d.), were elucidated using monosaccharide and methylation analysis, f.a.b.-m.s., and 1H-n.m.r. spectroscopy. The structures identified had two branching elements, ----4)[alpha-L-Araf-(1----3)]-beta-D-Xylp-(1---- and/or ----4) [alpha-L-Araf-(1----2)][alpha-L-Araf-(1----3)]-beta-D-Xyl p-(1----, directly connected to each other in all four possible combinations. The h.p.a.e.-p.a.d. elution pattern showed that these combinations are not present in equal amounts. Also, compounds containing two 2,3-branched beta-D-Xylp residues separated by one or two unbranched beta-D-Xylp residues were found, and the presence of a tetradecasaccharide containing three 2,3-branched beta-D-Xylp residues was established.
Hoffmann
R A
RA
Bijvoet Center, Department of Bio-Organic Chemistry, Utrecht University, The Netherlands.
Geijtenbeek
T
T
Kamerling
J P
JP
Vliegenthart
J F
JF
D001089:Arabinose / Q000032:analysis*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002852:Chromatography, Ion Exchange; D006026:Glycoside Hydrolases; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008961:Models, Structural; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds; D016339:Spectrometry, Mass, Fast Atom Bombardment; D014908:Triticum; D043325:Xylan Endo-1,3-beta-Xylosidase; D014994:Xylose / Q000032:analysis*
D009844:Oligosaccharides; D006859:Hydrogen; D014994:Xylose; D001089:Arabinose; D006026:Glycoside Hydrolases; D043325:Xylan Endo-1,3-beta-Xylosidase