Plant Mucilages. XI. Isolation and Characterization of a Mucous Polysaccharide, "Paniculatan, " from the Barks of Hydrangea paniculata

Abstract

A mucous polysaccharide, named paniculatan, has been isolated from the inner barks of Hydrangea paniculata SIEB. It was homogeneous by ultracentrifugal analysis and on glass-fiber paper electrophoresis. It was composed of L-rhamnose : D-galactose : 4-O-methyl-D-glucuronic acid : D-galacturonic acid in the molar ratio of 8 : 16 : 10 : 23. The O-acetyl groups in it were identified and the content was 2.0%. Molecular weight of its ammonium salt was estimated at 109000. Periodate oxidation study suggested that the polysaccharide has the high branching structure, whose terminals are occupied by all of 4-O-methyl-D-glucuronic acid units and by about three fourth of D-galacturonic acid units.