Convenient use of non-malodorous thioglycosyl donors for the assembly of multivalent globo- and isoglobosyl trisaccharides.
New thioglycosyl donors (o-methoxycarbonylphenyl 2,3,4,6-tetra-O-benzyl-1-thio-beta-D-galactopyranoside and its 6-O-acetyl analogue) were designed and used for the synthesis of glycoconjugate polymers carrying Gb(3) [Gal(alpha1-->4)Gal(beta1-->4)Glc] and isoGb(3) [Gal(alpha1-->3)Gal(beta1-->4)Glc] clusters as side chains. These donors scarcely evolved the unpleasant odor of thiophenols and showed a high alpha-anomeric selectivity in the galactosylation of p-nitrophenyl beta-lactoside derivatives, although in moderate yields. The derived trisaccharides were converted to multivalent carbohydrate ligands and were subjected to a biological assay with Shiga toxins. The multivalent Gb(3) ligand was highly active in inhibiting the toxicity, while the isoGb(3) ligand showed no activity, indicating that Stx-I discriminates between the carbohydrate structures.
Dohi
Hirofumi
H
Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Japan.
Nishida
Yoshihiro
Y
Takeda
Tae
T
Kobayashi
Kazukiyo
K
D002240:Carbohydrate Sequence; D008024:Ligands; D008969:Molecular Sequence Data; D013862:Thiogalactosides / Q000737:chemistry*; D014312:Trisaccharides / Q000138:chemical synthesis* / Q000737:chemistry
D008024:Ligands; D013862:Thiogalactosides; D014312:Trisaccharides; C113460:globotriose