A WATER-SOLUBLE POLYSACCHARIDE FROM THE LEAVES OF LITSEA-GARDNERI (LAURACEAE)

A neutral polysaccharide isolated from the water extract of the leaves of Litsea gardneri was composed mainly of xylose (70%) and small, approximately equimolar amounts of arabinose, mannose, galactose and glucose. Methylation analysis combined with GLC-MS, (1)[H] and (13)[C]NMR spectroscopy of the native and degraded polysaccharides indicated the presence of a 1 --> 4 linked beta-D-xylopyranosyl backbone. It is possible that some arabinofuranosyl residues were incorporated in the backbone of the polymer. Side chains were attached to O-2 of some of the xylopyranosyl residues in the polymer chain. The available evidence suggests that the side chains may be either single units of terminal arabinofuranosyl/xylopyranosyl residues or multiple unit side chains containing both arabinosyl and xylosyl residues.