Abstract
An acidic polysaccharide, designated as AMon-S, was isolated from the roots of Astragalus mongholicus BUNGE. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 7.6×104. It showed significant reticuloendothelial system-potentiating activity in a carbon clearance test. It is composed of L-arabinose : D-galactose : D-galacturonic acid : D-glucuronic acid in the molar ratio of 18 : 18 : 1 : 1, in addition to small amounts of O-adetyl groups and peptide moiety. A part of the hexuronic acid residues exist as the methyl esters. Methylation analysis, carbon-13 nuclear magnetic resonance and periodate oxidation studies enabled elucidation of its structural features and revealed mainly α-arabino-β-3, 6-galactan type structural units.
