STRUCTURE OF A WATER-SOLUBLE POLYSACCHARIDE SULFATE FROM THE RED SEAWEED JOCULATOR MAXIMUS MANZA

The main acidic polysaccharide, designated PS1, extracted from the red seaweed Joculator maximus Manza, consisted of D-galactose, L-galactos e, 2-O-methyl-L-galactose, D-xylose and sulfate (100:69:32:49:73 in mo lar ratio). Analysis based on partial hydrolysis led to the identifica tion of oligosaccharides indicating a repeating backbone of -->3)beta- D-Gal(1-->4)alpha-L-Gal(1-->. Within this structure, the (1-->4)-linke d L-galactose residue was shown by trideuteriomethylation to be partly 2-O-methylated. On the basis of results obtained from C-13-NMR spectr um analysis, controlled Smith degradation, specific 6-O-desulfation an d methylation analyses, all the xylose residue appeared to occur as a single unit branching in the beta-configuration at O-6 of the D-galact ose residue, while the sulfates were located at O-6 of the D-galactose residue and O-2 or O-3 of the L-galactose residue.