An Acidic Polysaccharide Having Activity on the Reticuloendothelial System from the Bark of Eucommia ulmoides

An acidic polysaccharide, named eucomman A, was isolated from the dried bark of Eucommia ulmoides oliv. It was homogeneous on electrophoresis and gel chromatography, and showed significant reticuloendothelial system-potentiating activity in a carbon clearance test. It is composed of L-arabinose: D-galactose: D-glucose: l-rhamnose: D-galacturonic acid in the molar ratio of 8:6:4:5:8 in addition to small amounts of peptide moiety. Its molecular mass was estimated to be 6.0 x 104. Methylation analysis, carbon-13 nuclear magnetic resonance and periodate oxidation studies enabled elucidation of its structural features.