NEW DATA ON THE STRUCTURE OF LAMINARAN FROM CHORDA-FILUM (L) LAM AND RESERVE GLUCANS FROM OTHER BROWN-ALGAE

M-chains of highly branched (1-->3),(1-->6)-beta-D-glucan (laminaran) isolated previously from the brown alga Chorda filum contain 1-glucosy lated and 1,6-bis-glucosylated D-mannitol residues, as shown by methyl ation analysis and enzymolysis. The latter structural element is found in laminarans for the first time. Structural investigation of laminar ans from six other brown algae shows that the polysaccharides consist predominantly of (1-->3)-linked beta-D-glucopyranose residues with a s mall number of (1-->6)-glycosidic bonds in chains and branching points . Mannitol residues was not detected in laminarans from two Cystoseira species.