Structural features of water-soluble novel polysaccharide components from the leaves of Tridax procumbens Linn.
Two water-soluble polysaccharide fractions, WSTP-IA and WSTP-IB were purified from the leaves of Tridax procumbens Linn. with graded ethanol precipitation followed by mild delignification and size-exclusion chromatography. WSTP-IA contained L-Araf and D-Galp in approximately 1:3 molar proportions, and WSTP-IB contained only D-Galp as the major sugar component. The results of methylation linkage analysis, and 1H and 13C NMR studies on the native and modified polysaccharides, indicated that WSTP-IA is an L-arabino-D-galactan with a beta-(1-->6)-D-galactan main chain in which at least one in every two D-Galp residues carries single residues of either L-Araf (alpha-/beta-) or beta-D-Galp end-group as substituents at O-3. WSTP-IB is a linear beta-(1-->6)-D-galactan. This is the first report of polysaccharides containing a beta-(1-->6)-D-galactan main chain isolated from plant sources.
Department of Biochemistry and Molecular Biology, Georgetown University Medical School, Washington, D.C. 20007.
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Davidson
D001089:Arabinose / Q000032:analysis; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D005685:Galactans / Q000737:chemistry* / Q000302:isolation & purification; D005690:Galactose / Q000032:analysis; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D010946:Plants, Medicinal / Q000737:chemistry*; D012995:Solubility; D014867:Water
D005685:Galactans; D007202:Indicators and Reagents; D014867:Water; D001089:Arabinose; C005653:arabinogalactan; D005690:Galactose