The occurence of laminarans was studied on far-eastern and tropical ma
rine brown algae. Laminarans from four far-eastern brown algae were st
udied structurally. All they are the low molecular weight 1 --> 3; 1 -
-> 6-beta-D-glucans, varying considerably in the content of the 1 -->
6-beta-bound glucose residues existent as branches of the core 1 --> 3
-beta-D-bound glucan chain. A glycosylated mannitol is part of the lam
inarans molecules.