Characterization of seven xyloglucan oligosaccharides containing from seventeen to twenty glycosyl residues.
The complete primary structures of seven oligosaccharide subunits of the xyloglucan secreted by suspension-cultured Acer pseudoplatanus cells were determined. The oligosaccharides, ranging in size from 17 to 20 glycosyl residues, were generated by treatment of the xyloglucan with an endo-beta-(1----4)-glucanase. The oligosaccharide components of a fraction obtained by Bio-Gel P-2 chromatography of enzyme-treated xyloglucan were further purified by normal-phase h.p.l.c. and then converted to the corresponding oligoglycosyl alditols by reduction with NaBH4. The oligoglycosyl alditols, after purification to near homogeneity by reversed-phase h.p.l.c., were structurally characterized by 1H-n.m.r. spectroscopy, fast-atom bombardment mass spectrometry (f.a.b.-m.s.), and analysis of their glycosyl-residue and glycosyl-linkage compositions. Novel structural elements of xyloglucans were observed in this study, including beta-D-xylopyranosyl and alpha-L-arabinofuranosyl-(1----3)-beta-D-xylopyranosyl sidechains. The results also extend our list of correlations between 1H-n.m.r. resonances and specific structural features of xyloglucans and thus enhance our ability to determine the structures of xyloglucans from various sources.
Hisamatsu
M
M
Complex Carbohydrate Research Center, University of Georgia, Athens 30602.
York
W S
WS
Darvill
A G
AG
Albersheim
P
P
D002240:Carbohydrate Sequence; D002478:Cells, Cultured; D002480:Cellulase / Q000378:metabolism; D002845:Chromatography; D008401:Gas Chromatography-Mass Spectrometry; D005936:Glucans; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D010944:Plants / Q000737:chemistry* / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism; D014990:Xylans
D005936:Glucans; D009844:Oligosaccharides; D011134:Polysaccharides; D014990:Xylans; C029353:xyloglucan; D002480:Cellulase