Synthesis of a heptasaccharide hapten related to an anomalous biantennary glycan-chain of human chorionic gonadotropin of a patient with choriocarcinoma. A stepwise approach.
A stereocontrolled synthesis of a heptasaccharide hapten, 8-methoxycarbonyloctyl 3-O-[2,4-di-O-(2-acetamido-2-deoxy-4-O-beta-D-galactopyranosyl-beta-D- glucopyranosyl)-alpha-D-mannopyranosyl]-6-O-alpha-D-mannopyranosyl-beta- D-mannopyranoside (2), is described employing the lactosaminyl donor 3,6-di-O-acetyl-2-deoxy-2-phthalimido-4-O-(2,3,4, 6-tetra-O-acetyl-beta-D-galactopyranosyl)-beta-D-glucopyranosyl bromide and the mannotriosyl glycosyl acceptor 8-ethoxycarbonyloctyl 2,4-di-O-benzyl-3-O-(3,6-di-O-benzyl-alpha-D-mannopyranosyl)-6-O-(2,3, 4,6-tetra-O-benzyl-alpha-D-mannopyranosyl)-beta-D-mannopyranoside, the reaction of which gave the biantennary structure 8-ethoxycarbonyloctyl 2,4-di-O-benzyl-3-O-(3,6- di-O-benzyl-2,4-di-O-[3,6-di-O-acetyl-2-deoxy-2-phthalimido-4-O-(2,3, 4,6-tetra-O-benzyl-alpha-D-mannopyranosyl)-beta-D-mannopyranoside (9), as well as a monoglycosylated product, 8-ethoxycarbonyloctyl 2,4-di-O-benzyl-3-O-(3,6-di-O-benzyl-4-O-[3,6- di-O-acetyl-2-deoxy-2-phthalimido-4-O-(2,3,4,6- tetra-O-benzyl-alpha-D-mannopyranosyl)-beta-D-mannopyranoside. The diglycosylated product 9 was transformed into 2, and the structure was confirmed by 1H-n.m.r. data.
D000595:Amino Acid Sequence; D002822:Choriocarcinoma / Q000378:metabolism*; D006063:Chorionic Gonadotropin / Q000138:chemical synthesis* / Q000302:isolation & purification; D005260:Female; D006241:Haptens; D006801:Humans; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000138:chemical synthesis*; D011247:Pregnancy; D014594:Uterine Neoplasms / Q000378:metabolism*
D006063:Chorionic Gonadotropin; D006241:Haptens; D007202:Indicators and Reagents; D009844:Oligosaccharides