title: Synthesis of the sugar moiety of TIME-EA4, a glycopeptide isolated from silkworm diapause eggs.
abstract: We describe the efficient synthesis of the tetrasaccharide, 2-O-acetyl-3,4,6-tri-O-benzyl-alpha-D-mannopyranosyl-(1-->6)-2,4-di-O-acetyl-3-O-allyl-beta-D-mannopyranosyl-(1-->4)-3,6-di-O-benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl-(1-->4)-3,6-di-O-benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl azide, which is the protected form of the sugar unit of TIME-EA4 that is isolated from the diapausing eggs of the silkworm, Bombyx mori. The beta-linked D-mannoside of the tetrasaccharide was obtained using the conventional oxidation-reduction method for inversion of the configuration at the C-2 hydroxyl group of beta-D-glucoside. The reduction was effected with NaBH(4) in a methanolic solution in a ratio of 98:2 in favor of the beta-D-mannoside that was obtained in 87% yield.
authors.affiliation: Department of Material Science, Graduate School of Science, Osaka City University, Japan.
authors.forename: Shouji
authors.initials: S
authors.lastname: Hiro
authors.forename: Yoshinosuke
authors.initials: Y
authors.lastname: Usuki
authors.forename: Hideo
authors.initials: H
authors.lastname: Iio
mesh_terms: D000818:Animals; D012831:Bombyx / Q000737:chemistry*; D002240:Carbohydrate Sequence; D005260:Female; D006020:Glycopeptides / Q000737:chemistry*; D006027:Glycosides / Q000138:chemical synthesis* / Q000737:chemistry; D006031:Glycosylation; D009682:Magnetic Resonance Spectroscopy; D008362:Mannosides / Q000737:chemistry; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D010063:Ovum / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: C513605:2-O-acetyl-3,4,6-tri-O-benzyl-alpha-D-mannopyranosyl-(1-6)-2,4-di-O-acetyl-3-O-allyl-beta-D-mannopyranosyl-(1-4)-3,6-di-O-benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl-(1-4)-3,6-di-O-benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl azide; D006020:Glycopeptides; D006027:Glycosides; D008362:Mannosides; D009844:Oligosaccharides