A POLYSACCHARIDE FRACTION FROM THE RED SEAWEED CHAMPIA-NOVAE-ZEALANDIAE RHODYMENIALES, RHODOPHYTA

The polysaccharide recovered after extraction of Champia novae-zealand iae is a galactan with alternating 3-linked D-galactopyranosyl units s ulfated at the 2-position, and 4-linked galactopyranosyl units sulfate d at both the 2- and 3-positions that are predominantly of the L- and partly of the D-configuration. Other minor substitution includes 6-O-m ethyl ether or 4,6-pyruvate acetal on the 3-linked residues. Technique s used in determining the structure include infrared and C-13-NMR spec troscopy, and GC-MS analysis of alditol acetate derivatives produced b y reductive hydrolysis/acetylation of native, methylated, and/or desul fated samples. These results are of particular interest because 4-link ed 2,3-disulfated galactosyl residues have not been encountered as maj or constituents of red algal polysaccharides.