Structural characterization of the pectic polysaccharide, rhamnogalacturonan-II.
An octasaccharide was released from sycamore cell wall rhamnogalacturonan-II (RG-II) by selective acid hydrolysis of the glycosidic linkages of apiosyl residues and purified to homogeneity by gel-permeation and high-performance anion-exchange chromatographies. The octasaccharide 1 contains a terminal nonreducing beta-L-arabinofuranosyl residue linked to position 2 of the alpha-L-rhamnopyranosyl residue of the aceric acid-containing heptasaccharide 2 that had been previously isolated from RG-II [M.W. Spellman et al. Carbohydr. Res., 122 (1983) 131-153]. Heptasaccharide 2 and octasaccharide 1 were found to be mono- or di-O-acetylated. The O-acetyl groups were located, by ESMSMS, on the terminal nonreducing 2-O-methyl-alpha-L-fucosyl residue and/or on the 2-linked beta-L-aceryl acid residue. Octasaccharide 1 and heptasaccharide 2 have the following structures: [structure: see text]
Whitcombe
A J
AJ
Complex Carbohydrate Research Center, University of Georgia, Athens 30602-4712, USA.
O'Neill
M A
MA
Steffan
W
W
Albersheim
P
P
Darvill
A G
AG
D001894:Borohydrides; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D006868:Hydrolysis; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry / Q000302:isolation & purification; D010368:Pectins / Q000737:chemistry*; D013402:Sugar Alcohols / Q000032:analysis
D001894:Borohydrides; D009844:Oligosaccharides; D013402:Sugar Alcohols; C042492:rhamnogalacturonan II; C025364:sodium borohydride; D010368:Pectins