1. Synthesis of the Core Oligosaccharides of Lipooligosaccharides from Campylobacter jejuni: A Putative Cause of Guillain-Barré Syndrome
- Author
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Shinya Hanashima, Hideharu Ishida, Hiroki Yoshinaka, Mikio Ishihara, Yoshiki Yamaguchi, Akihiro Imamura, Fumi Yoshida, Hiromune Ando, Risa Saito, Yuki Kato, Hidenori Tanaka, Makoto Kiso, and Miyuki Saburomaru
- Subjects
Lipopolysaccharides ,Glycan ,Glycosylation ,Magnetic Resonance Spectroscopy ,Stereochemistry ,Oligosaccharides ,010402 general chemistry ,Guillain-Barre Syndrome ,01 natural sciences ,Campylobacter jejuni ,Chemical synthesis ,Catalysis ,chemistry.chemical_compound ,Gangliosides ,Campylobacter Infections ,Monosaccharide ,Humans ,chemistry.chemical_classification ,Ganglioside ,biology ,010405 organic chemistry ,Organic Chemistry ,Glycoside ,Glycosidic bond ,General Chemistry ,biology.organism_classification ,0104 chemical sciences ,chemistry ,biology.protein ,Trisaccharides - Abstract
The chemical synthesis of the highly branched core oligosaccharides of lipooligosaccharides (LOSs) found in Campylobacter jejuni, which causes Guillain-Barre syndrome by a preceding infection, is described. The target LOS mimics, consisting of eight or nine monosaccharides, were classified into three groups as key building blocks: ganglioside-core tetra-/pentasaccharides (GM1-/GD1a-like), l-glycero-d-manno-heptose-containing trisaccharides, and 3-deoxy-d-manno-2-octulosonic acid (KDO) residues. These synthetic fragments were obtained from commercially available monosaccharides. Less obtainable l-glycero-d-manno-heptose and KDO residues, as key components of the LOSs, were synthesized from p-methoxyphenyl d-mannoside and di-O-isopropylidene-protected d-mannose, respectively. The synthesis of α-KDO glycoside, as one of the most difficult stereocontrolled glycosidic constructions, was achieved by treating a 2,3-ene derivative of KDO with phenylselenyl trifluoromethanesulfonate as a suitable α-directing reagent. All synthetic blocks were constructed through a convergent synthetic route, which resulted in the first synthesis of structurally challenging LOS core glycans containing ganglioside GM1 and GD1a-core sequences.
- Published
- 2018