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.
Synthesis, NMR and Conformational Studies of Fucoidan Fragments 1:<sup>1</sup>Desulfated 2,3- and 3,4-Branched Trisaccharide Fragments and Constituting Disaccharides
作者:Elena A. Khatuntseva、Nadezhda E. Ustuzhanina、Georgij V. Zatonskii、Alexander S. Shashkov、Anatoly I. Usov、Nikolay E. Nifant'ev
DOI:10.1080/07328300008544140
日期:2000.1.1
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.
Acid-promoted synthesis of per-O-sulfated fucooligosaccharides related to fucoidan fragments
作者:Vadim B. Krylov、Zinaida M. Kaskova、Dmitry Z. Vinnitskiy、Nadezhda E. Ustyuzhanina、Alexey A. Grachev、Alexander O. Chizhov、Nikolay E. Nifantiev
DOI:10.1016/j.carres.2011.01.005
日期:2011.4
has been performed with the use of previously reported acid-promoted protocol for per-O-sulfation of polyols by SO(3) complexes. During the treatment of (1-->3)-linked oligofucosides under these conditions with the promotion by TfOH, the unusual rearrangement of the reducing pyranose residue into furanose one was observed. To avoid the formation of rearrangement by-products, the use of a series of strong