Location of the O-acetyl substituents on a nonasaccharide repeating unit of sycamore extracellular xyloglucan.
The locations of the O-acetyl substituents on the major nonasaccharide repeating unit of the xyloglucan isolated from sycamore extracellular polysaccharides were determined by a combination of analytical methods, including f.a.b.-m.s. and 1H-n.m.r. spectroscopy. The O-2-linked-beta-D-galactosyl residue of the nonasaccharide was found to be the dominant site of O-acetyl substitution. Both mono-O-acetylated and di-O-acetylated beta-D-galactosyl residues were detected. The degree of O-acetylation of the beta-D-galactosyl residue, was estimated by 1H-n.m.r. spectroscopy to be 55-60% at O-6, 15-20% at O-4, and 20-25% at O-3. 1H-n.m.r. spectroscopy also indicated that approximately 50% of the beta-D-galactosyl residues are mono-O-acetylated, 25-30% are di-O-acetylated, and 20% are not acetylated.
York
W S
WS
Complex Carbohydrate Research Center, University of Georgia, Athens 30613.
Oates
J E
JE
van Halbeek
H
H
Darvill
A G
AG
Albersheim
P
P
Tiller
P R
PR
Dell
A
A
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005936:Glucans; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis*; D010944:Plants / Q000032:analysis*; D011134:Polysaccharides; D014990:Xylans
D005936:Glucans; D009844:Oligosaccharides; D011134:Polysaccharides; D014990:Xylans; C029353:xyloglucan