Kazuyo Shimada

Relationship between chemical structure and anti-complementary activity of plant polysaccharides

Abstract Seventeen water-soluble polysaccharides obtained from various plants were tested for anti-complementary activities. Considerable activity was observed for Zizyphus-arabinan [(1→5)-linked α- l -arabinofuranosyl main-chain having (1→2)-linked α- l -arabinofuranosyl side-chains] from the dried fruit of Zizyphus jujuba var. inermis , paniculatan [highly branched, partially O -acetylated, acidic mucous polysaccharide composed of (1→2)-linked α- l -rhamnopyranosyl residues having branches composed of O -(4- O -methyl-α- d -glucopyranosyluronic acid)-(1→4)-β- d -galactopyranose at position 4 and (1→4)-linked α- d -galactopyranosyluronic acid residues having β- d -glucosyluronic acid groups at position 3] from the inner bark of Hydrangea paniculata , and Plantago-mucilage A [highly branched, partially O -acetylated, acidic mucous polysaccharide with a main chain of (1→4)-linked β- d -xylopyranosyl residues having other β- d -xylopyranosyl groups and branches composed of O -(α- d -glucopyranosyluronic acid)-(1→3)-α- l -arabinofuranosyl and O -(α- d -galactopyranosyluronic acid)-(1→3)-α- l -arabinofuranosyl groups at position 3 as side chains] from the seed of Plantago asiatica . The majority of the mucous acidic polysaccharides from the plants belonging to Malvaceae had weak activities. These polysaccharides commonly contained (1→2)-α- l -rhamnopyranosyl-(1→4)-α- d -galactopyranosyluronic acid residues as the main chain. Glucomannans and pectin did not show any significant activity. The results of tests on C4 titration, anti-complementary activity in the absence of Ca 2+ , crossed immunoelectrophoresis, and activity of the alternative complement pathway using rabbit erythrocytes indicated that the mode of complement activation by paniculatan occurred mainly via the classical pathway, whereas activation by Zizyphus-arabinan and Plantago-mucilage A were both via the alternative and classical pathways. The mode of complement activation by paniculatan did not depend on its particulate state.

Structure of panaxan B, a hypoglycaemic glycan of Panax ginseng roots☆

Abstract A hypoglycaemic principle, panaxan B, obtained from the roots of Panax ginseng , was shown to be a peptidoglycan with M r of about 1 800 000. Physico-chemical and chemical studies indicated panaxan B to be mainly composed of α-1 → 6 linked D -glycopyranose residues with branching at the C-3 position, the ratio of terminals, branching positions and intermediate units being about 1:1:1.8.

The carbohydrate structure of a mucilage from the roots of Hibiscus moscheutos L.

Abstract A representative mucilage, named Hibiscus-mucilage Mo, was isolated from the roots of Hibiscus moscheutos L.; it was homogeneous by ultracentrifugal analysis, electrophoresis, and gel chromatography. Its intrinsic viscosity in aqueous solution was 32.2. It is a partially acetylated, acidic polysaccharide of molecular weight ≈1,900,000, and is composed of l -rhamnose: d -galacturonic acid: d -glucuronic acid in approximately equimolar ratio. Methylation of the carboxyl-reduced derivative and partial hydrolysis studies indicated a repeating unit of the following structure.