A practical synthesis of beta-D-GlcA-(1-->3)-beta-D-Gal-(1-->3)-beta-D-Gal-(1-->4)-D-Xyl, a part of the common linkage region of a glycosaminoglycan.
A practical synthesis of beta-D-GlcA-(1-->3)-beta-D-Gal-(1-->3)-beta-D-Gal-(1-->4)-beta-D-Xyl-(1-->OMe) was achieved by coupling of methyl 2,3,4-tri-O-acetyl-alpha-D-glucopyranosyluronate trichloroacetimidate with a trisaccharide acceptor. The trisaccharide acceptor was obtained by condensation of 3-O-allyl-2,4,6-tri-O-benzoyl-beta-D-galactopyranosyl-(1-->3)-2,4,6-tri-O-benzoyl-alpha-D-galactopyranosyl trichloroacetimidate with methyl 2,3-di-O-benzoyl-beta-D-xylopyranoside, followed by deallylation. The beta-(1-->3)-linked disaccharide was prepared readily with p-methoxyphenyl 3-O-allyl-2,4,6-tri-O-benzoyl-beta-D-galactopyranoside as the key synthon. The alpha-(1-->3)-linkage was formed in considerable amount with galactose mono- and disaccharide trichloroacetimidate donors with C-2 neighboring group participation.
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, China.
Langqiu
L
Chen
Fanzuo
F
Kong
D002240:Carbohydrate Sequence; D005690:Galactose / Q000138:chemical synthesis* / Q000737:chemistry*; D005947:Glucose / Q000138:chemical synthesis* / Q000737:chemistry*; D006025:Glycosaminoglycans / Q000737:chemistry*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry*; D013379:Substrate Specificity; D014994:Xylose / Q000138:chemical synthesis* / Q000737:chemistry
D006025:Glycosaminoglycans; D009844:Oligosaccharides; D014994:Xylose; D005947:Glucose; D005690:Galactose