Synthesis of the saccharide moiety of galactosylgloboside (SSEA-3) and its conjugation to bovine serum albumin and Sepharose.
The pentasaccharide glycoside corresponding to galactosylgloboside (SSEA-3), beta-D-Gal p-(1-->3)-beta-D-Gal pNAc-(1-->3)-alpha-D-Gal p-(1-->4)-beta-D-Gal p-(1-->4)-beta-D-Glc p-1-OCH2CH2Si-(CH3)3 (4), was synthesized via glycosylation (87%) of 2-(trimethylsilyl)ethyl 2,3,6-tri-O-benzyl-4-O-[2,3,6-tri-O-benzyl-4-O-(2,4, 6-tri-O-benzyl-alpha-D-galactopyranosyl)-beta-D-galactopyranosyl]-beta-D - glucopyranoside (2) with the glycosyl donor methyl 4,6-di-O-acetyl-2-deoxy-2-phthalimido-3-O-(2,3,4, 6-tetra-O-acetyl-beta-D-galactopyranosyl)-1-thio-beta-D-galactopyranosid e (1), followed by removal of protecting groups. Compound 4 was transformed into the spacer glycoside beta-D-Gal p(1-->3)-beta-D-Gal pNAc-(1-->3)-alpha-D-Gal p-(1-->4)-beta-D-Gal p-(1-->4)-beta-D-Glc p-1-SCH2CH2COOH (10), which was coupled to bovine serum albumin (BSA), and Sepharose beads, to give the corresponding neoglycoprotein (11, 6 mol of saccharide/mol of BSA), and glycosylated Sepharose (12, 2.7 mumol of saccharide/mL of sedimented beads), respectively. An improved synthesis of a protected globotetraoside beta-D-Gal pNAc-(1-->3)-alpha-D-Gal p-(1-->4)-beta-D-Gal p-(1-->4)-beta-D-Glc p-1-OCH2CH2SiMe3 is also reported.
Nilsson
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U
Chemical Center, Lund Institute of Technology, University of Lund, Sweden.
Magnusson
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G
D015295:Antigens, Tumor-Associated, Carbohydrate; D002240:Carbohydrate Sequence; D005915:Globosides / Q000138:chemical synthesis; D006028:Glycosphingolipids / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009844:Oligosaccharides / Q000138:chemical synthesis*; D012685:Sepharose / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D055746:Stage-Specific Embryonic Antigens
D015295:Antigens, Tumor-Associated, Carbohydrate; D005915:Globosides; D006028:Glycosphingolipids; D009844:Oligosaccharides; D055746:Stage-Specific Embryonic Antigens; C052924:stage-specific embryonic antigen-3; D012710:Serum Albumin, Bovine; D012685:Sepharose