Structural study of fucoidan from Cladosiphon okamuranus TOKIDA.
A structural study was carried out on a fucoidan isolated from the brown seaweed Cladosiphon okamuranus. The polysaccharide contained fucose, glucuronic acid and sulfate in a molar ratio of about 6.1 : 1.0 : 2.9. The results of Smith degradation showed that this polysaccharide has a linear backbone of 1-->3-linked alpha-fucopyranose with a half sulfate substitution at the 4-positions, and a portion of the fucose residues was O-acetylated. The data obtained from partial acid hydrolysis, a methylation analysis and NMR spectra indicated that the alpha-glucuronic acid residue is linked to the 2-positions of the fucose residues, which were not substituted by a sulfate group. These results indicated that the average structure of this fucoidan is as follows: -[(-->3Fuc-4(+/-OSO3-)alpha1-)5-->3[GlcA alpha1-->2]Fuc alpha1-]n-. (Half of each fucose residue was sulfated. One O-acetyl ester was present in every 6 fucose residues.)
Nagaoka
M
M
Yakult Central Institute for Microbiological Research, Tokyo, Japan.
Shibata
H
H
Kimura-Takagi
I
I
Hashimoto
S
S
Kimura
K
K
Makino
T
T
Aiyama
R
R
Ueyama
S
S
Yokokura
T
T
D015394:Molecular Structure; D011134:Polysaccharides / Q000737:chemistry*; D012624:Seaweed / Q000737:chemistry*
D011134:Polysaccharides; C007789:fucoidan