title: Synthesis and NMR analysis of model compounds related to fucosylated chondroitin sulfates: GalNAc and Fuc(1 → 6)GalNAc derivatives.
abstract: Unsubstituted and 6-O-α-L-fucosylated propyl 2-acetamido-2-deoxy-β-D-galactopyranosides and their selectively O-sulfated (both in GalNAc and Fuc units) derivatives were synthesized as model compounds representing the fragments of fucosylated chondroitin sulfates (FCS) from sea cucumbers. Per-O-acetylated 2-deoxy-2-N-phthalimido-D-glucopyranose was used as a key precursor for the preparation of all 2-acetamido-2-deoxy-D-galactopyranoside containing products. Attempts at 6-O-glycosylation of propyl 3-O-benzoyl-2-deoxy-2-N-phthalimido-D-galactoside by 2-O-benzyl-3,4-di-O-chloracetyl-L-fucosyl trichloracetimidate in the presence of TMSOTf gave a 1:1 mixture of the corresponding α- and β-isomeric disaccharides, while the use of structurally related fucosyl bromide donor with promotion by Bu4NBr led to the formation of desired α-isomeric disaccharide exclusively. Selective removal of orthogonal O-protections permitted subsequent O-sulfation both at the GalNAc and Fuc units. Further removal of blocking groups yielded the target products which were systematically studied by1H and13C NMR spectroscopy in order to determine the spectral effects of O-sulfation and α-L-fucosylation needed for the development of computer assisted structural analysis of natural FCS.
authors.affiliation: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow 119991, Russia.
authors.forename: Dmitry Z
authors.initials: DZ
authors.lastname: Vinnitskiy
authors.affiliation: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow 119991, Russia. Electronic address: ustnad@gmail.com.
authors.forename: Nadezhda E
authors.initials: NE
authors.lastname: Ustyuzhanina
authors.affiliation: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow 119991, Russia.
authors.forename: Andrey S
authors.initials: AS
authors.lastname: Dmitrenok
authors.affiliation: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow 119991, Russia.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.affiliation: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, Moscow 119991, Russia. Electronic address: nen@ioc.ac.ru.
authors.forename: Nikolay E
authors.initials: NE
authors.lastname: Nifantiev
mesh_terms: D002809:Chondroitin Sulfates / Q000138:chemical synthesis* / Q000737:chemistry; D006031:Glycosylation; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: C517150:fucosylated chondroitin sulfate; D002809:Chondroitin Sulfates
keywords: Fucosylated chondroitin sulfate; Glycosylation; NMR; Oligosaccharide; Spectral glycosylation effect; Spectral sulfation effect; Synthesis