Structural study of fucoidan from Cladosiphon okamuranus tokida

Cladosiphon okamuranus fucoidan has a linear backbone of α-(1-3)-fucopyranose, half of which is sulfate substituted at C4, and some fucopyranoses are O-acetylated.

“Among them, Cladosiphon okamuranus from the order Chordariales showed a linear backbone of α-(1-3)-fucopyranose, half of which was sulfate substituted at the C4 position. Some fucopyranoses were O-acetylated [8].”

C. okamuranus FCSPs may contain α-glucuronic acid substitutions at C-2 positions of backbone fucose residues not substituted by sulfate.

“The C. okamuranus FCSPs may also contain α-glucuronic acid substitutions at the C-2-positions of those backbone fucose residues that are not substituted by a sulfate group [14] (Figure 4).”

Other algal fucoidans with the same α(1→3)-backbone of fucose residues have been found in Analipus japonicas, Adenocystis utricularis and Cladosiphon okamuranus, but FCSPs from these brown algae also appear to contain monosaccharides other than fucose.

“Other algal fucoidans whose structures contain the same α(1→3)-backbone of fucose residues have been found in Analipus japonicas (Ectocarpales), Adenocystis utricularis (Ectocarpales) and Cladosiphon okamuranus (Chordariales) [14,15,39], but the FCSPs from these brown algae also appear to contain other monosaccharides than fucose (Table 2).”

FCSPs from C. okamuranus exert virtually no anticoagulant effect, possibly due to low sulfate in the polymer backbone and/or presence of vicinal branching points formed by 2-O-α-d-glucuronyl substituents.

“FCSPs from C. okamuranus (Chordariales) have been reported to exert virtually no anticoagulant effect, and this could be due to the low amount of sulfate in its polymer backbone and/or the presence of vicinal branching points formed by 2-O-α-d-glucuronyl substituents (Figure 4) [21,14].”

Fucoidans from Cladosiphon okamuranus are basically made up of linear backbones of α(1→3)-linked L-fucopyranose residues with a portion of the fucose residues being O-acetylated and with some sulfate substitution at C-4.

“Similarly, the fucoidans from Cladosiphon okamuranus (Chordariales) are basically made up of linear backbones of a(1A3)-linked L- fucopyranose residues (Table 1) with a portion of the fucose residues being O-acetylated and with some sulfate substitution at the C-4 position.8”