AN ACIDIC POLYSACCHARIDE WITH IMMUNOLOGICAL ACTIVITIES FROM THE ROOT OF PEONIA-LACTIFLORA

An acidic polysaccharide, called peonan PA, was isolated from the root of Paeonia lactiflora PALLAS. It was homogeneous on electrophoresis a nd gel chromatography, and its molecular mass was estimated to be 6.0 x 10(4). Peonan PA is composed of L-arabinose: D-galactose: D-galactur onic acid in the molar ratio of 2:1:10, in addition to small amounts o f O-acetyl groups and peptide moieties. About forty percent of the hex uronic acid residues in peonan PA exist as methyl esters. Reduction of carboxyl groups, methylation analysis, lithium degradation and nuclea r magnetic resonance studies indicated that its main structural featur es involve both alpha-1,5-linked L-arabino-beta-3,6-branched D-galacta n type and alpha-1,4-linked D-galacturoan type structural units. The p olysaccharide exhibited remarkable reticuloendothelial system-potentia ting activity in a carbon clearance test and considerable anti-complem entary activity.