Abstract
Paniculatan, the mucous polysaccharide isolated from the inner barks of Hydrangea paniculata SIEB., was found to be composed of L-rhamnose : D-galactose : D-galacturonic acid : D-glucuronic acid : 4-O-methyl-D-glucuronic acid in the approximate molar ratio of 4 : 4 : 3 : 2 : 5. The mucilage has been subjected to the reduction of carboxyl groups and to controlled Smith degradation. As the results of methylation analysis of these products and the original polysaccharide, possible structures of the backbone chain were proposed. The chain is composed of 1→2 linked L-rhamnopyranose residues having branches at position 4 and 1→4 linked D-galactopyranosyluronic acid residues having branches at position 3 in the approximate molar ratio of 2 : 1.