Synthesis, NMR and Conformational Studies of Fucoidan Fragments 1:1Desulfated 2,3- and 3,4-Branched Trisaccharide Fragments and Constituting Disaccharides
摘要:
Two fucotriosides with vicinal disubstitution alpha -L-Fuc-(1-->2)[alpha -L-Fuc-(1-->3)[alpha -L-Fuc-OPr (1) and alpha -L-Fuc-(1-->3)[alpha -L-Fuc-(1-->4)]alpha -L-Fuc-OPr (2), which are related to fragments of natural polysaccharides fucoidans, have been synthesized together with constituent disaccharides 3-5, Spectral and conformational properties of tri- and disaccharides have been investigated by (1)H, (13)C and NOE NMR spectroscopy.
A highly regular fraction of a fucoidan from the brown seaweed Fucus distichus L.
作者:Maria I Bilan、Alexey A Grachev、Nadezhda E Ustuzhanina、Alexander S Shashkov、Nikolay E Nifantiev、Anatolii I Usov
DOI:10.1016/j.carres.2003.10.028
日期:2004.2
A fucoidan fraction consisting Of L-fucose, sulfate, and acetate in a molar proportion of 1:1.21:0.08 was isolated from the brown seaweed Fucus distichus collected from the Barents Sea. The C-13 NMR spectrum of the fraction was typical of regular polysaccharides containing disaccharide repeating units. According to 1D and 2D H-1 and 13 C NMR spectra, the fucoidan molecules are built up of alternating 3-linked alpha-L-fucopyranose 2,4-disulfate and 4-linked alpha-L-fucopyranose 2-sulfate residues: --> 3)-alpha-L-Fucp-(2,4-di-SO3-)-(1 --> 4)-alpha-L-Fucp-(2SO(3)(-))-(1 -->. The regular structure may be only slightly masked by random acetylation and undersulfation of several disaccharide repeating units. (C) 2003 Elsevier Ltd. All rights reserved.