Structural studies on a novel fucogalactan sulfate extracted from the brown seaweed Laminaria japonica.
A low molecular weight fucogalactan, obtained from the brown seaweed Laminaria japonica, was separated into three fractions (LF1, LF2 and LF3) by DEAE-Sepharose FF column chromatography. All three fractions contained predominantly fucose, sulfate group and galactose. The results showed that the main fraction LF2 consisted of l-fucose, d-galactose and sulfate at a molar ratio 6:1:9. Structural study on the LF2 was carried out by NMR spectroscopy. The backbone of LF2 was primarily (1-->3)-linked alpha-l-fucopyranose residues (75%) and a few (1-->4)-alpha-l-fucopyranose linkages (25%). The branch points were at C-4 of 3-linked alpha-l-fucopyranose residues by beta-d-galactopyranose unites (35%, molar ratio) or at C-2 of 3-linked alpha-l-fucopyranose residues by non-reducing terminal fucose unites (65%, molar ratio). Sulfate groups occupied at position C-4 or C-2, sometimes C-2, 4 to fucose residues, and C-3 and/or C-4 to galactose residues. The structure of LF2 was supposed as following: .
Wang
Jing
J
Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China.
Zhang
Quanbin
Q
Zhang
Zhongshan
Z
Zhang
Hong
H
Niu
Xizhen
X
D002240:Carbohydrate Sequence; D005591:Chemical Fractionation; D005685:Galactans / Q000737:chemistry* / Q000302:isolation & purification*; D007795:Laminaria / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data
D005685:Galactans