Plant Mucilages. XXXVII. A Representative Mucilage, "Althaea-Mucilage RL, " from the Leaves of Althaea rosea

A representative mucilage, named Althaea-mucilage RL, was isolated from the leaves of Althaea rosea CAVAILLES. The final preparation was homogeneous as determined by ultracentrifugal analysis, electrophoresis, and gel chromatography. Its water solution gave an intrinsic viscosity value of 32. 5. It was mainly composed of partially acetylated acidic polysaccharide, and its molecular weight was estimated to be about 1800000. The polysaccharide was composed of L-rhamnose : D-galactose : D-galacturonic acid : D-glucuronic acid : O-acetyl groups in the approximately molar ratio of 20 : 1 : 16 : 16 : 10. Methylation and partial hydrolysis studies made it possible to deduce the structural features of the polysaccharide moiety in the mucilage.