Synthesis of neoglycolipids containing a mucin-type core unit.
The unnatural glycolipids O-beta-D-galactopyranosyl-(1-->4)-O-(2-acetamido- 2-deoxy-beta-D-glucopyranosyl)-(1-->3)-O-(2-acetamido-2-deoxy-alpha-D- galactopyranosyl)-(1-->1)-ceramide (1), O-beta-D-galactopyranosyl-(1-->4)-O-(2-acetamido-2-deoxy-beta-D-glucopyr anosyl) - (1-->6)-O-(2-acetamido-2-deoxy-alpha-D-galactopyranosyl)-(1-->1)-ceramid e (2), and O-beta-D-galactopyranosyl-(1-->4)-O-(2-acetamido-2-deoxy-beta-D- glucopyranosyl)-(1-->3)-O-[O-beta-D-galactopyranosyl-(1-->4)-(2-acetamid o-2- deoxy-beta-D-glucopyranosyl)-(1-->6)]-O-(2-acetamido-2-deoxy-alpha-D- galactopyranosyl)-(1-->1)-ceramide (3), and their beta-(1-->1)-linked isomers, were synthesized. The precursor oligosaccharides for 1, 2, and 3 were made by coupling O-2,3,4,6- tetra-O-acetyl-beta-D-galactopyranosyl)-(1-->4)-3,6-di-O-acetyl-2- deoxy-2-phthalimido-alpha,beta-D-glucopyranosyl trichloroacetimidate with tert-butyldiphenylsilyl 2-azido-4,6-O-benzylidene-2-deoxy-beta-D-galactopyranoside, tert-butyldiphenylsilyl 2-azido-3-O-benzoyl-2-deoxy-beta-D-galactopyranoside, and tert-butyl-diphenylsilyl O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-(1-->4)-O-(3,6-di-O-a cetyl-2 - deoxy-2-phthalimido-beta-D-glucopyranosyl)-(1-->3)-2-azido-2-deoxy-beta- D- galactopyranoside, respectively. These oligosaccharides were converted into their trichloroacetimidates, which were coupled with 3,2'-di-O-benzoyl ceramide. Deprotection of the coupling products gave the title compounds 1, 2, and 3.
Horie
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R
Biotechnology Research Laboratory, TOSOH Corporation, Kanagawa, Japan.
Nakano
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K
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D006017:Glycolipids / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009077:Mucins / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
D006017:Glycolipids; D009077:Mucins