The polysaccharides isolated from the defatted seeds of Salmalia malabarica (Bombacaceae) were fractionated into Fractions I (48%), II (30%), III (14%), and IV (8%) using a column of Sephadex G-100 in pyridine-acetate buffer. The principal polysaccharide fraction, Fraction I (carbohydrate content' 98%), was found to be electrophoretically homogeneous. Hydrolysis (M sulfuric acid, 16 h, 100') of Fraction I revealed galactose and arabinose (Table I) by paper chromatography in a relative ratio of 7:3 as determined by gas-liquid chromatography (g.1.c.) oftheir alditol acetates'using myo-inositol as the internal standard. The configuration of the galactose and arabinose were determined as D and L, respectively, from their optical rotation measurements (see Experimental section). Complete methylation of Fraction I by the Hakomori method" and hydrolysis of the methylated polysaccharide yielded 2,3,5-tri-O-methyl-~arabinofuranose (4.1 mol. equiv.), 2,3,4-tri-O-methyl-L-arabinopyranose (11 mol. equiv.), 2,3,4,6-tetra-O-methyl-D-galactose (0.85 mol. equiv.), 2,3,6-tri-O-methyl-D-galactopyranose (10.8 mol. equiv.), 2,4,6-tri-O-methyl-D-galactopyranose (2.2 mol. equiv.), 3,6di-0-methyl-D-galactose (12.4 mol. equiv.), and 3.4-di-0-methyl-D-galactose (7.0 mol. equiv.) (see Table II). These products reveal that both L-arabinopyranose and Larabinofuranose are present at the non-reducing ends. A small number of the nonreducing termini are occupied by D-galactose. Appearance of a large molar proportion of the tri-O-methyl pentoses shows that the polysaccharide is highly branched. The major portion of the interior part consists of D-galactose residues linked (l-+2,6) and (l--+2,4). A portion of the chain was made by D-galactose linked principally 1+4. There was a small portion of D-galactose residues linked (1 + 3). The polysaccharide Fraction I consumed about 0.9 mol. equiv. of periodate per mole of hexosyl residue as was monitored spectrophotometrically4.'.
Only D-galactose was detected in the paper chromatogram when the periodate-oxidised, borohydride-reduced material was hydrolyzed with sulfuric acid (0.5~). This observation was in fair agreement with the linkage pattern as suggested from the methylation analysis.