title: Synthesis of a peripheral trisaccharide sequence of lutropin, a pituitary glycoprotein hormone; use of chitobiose as a key starting material.
abstract: A chitobiose derivative, methyl O-(3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl)-(1--- -4)-3,6 - di-O-acetyl-2-deoxy-2-phthalimido-beta-D-glucopyranoside, was derived from the corresponding N-acetyl derivative and this was converted into the glycosyl bromide (5). Glycosidation reaction between 5 and methyl 3,4,6-tri-O-benzyl-alpha-D-mannopyranoside in the presence of silver trifluoromethanesulfonate gave a beta-D-linked trisaccharide derivative. Replacement of the N,N-phthaloyl group by acetyl groups resulted in a product that was converted into methyl O-(2-acetamido-3,6-di-O-benzyl-2-deoxy-beta-D-glucopyranosyl)-(1----4)-O -(2- acetamido-3,6-di-O-benzyl-2-deoxy-beta-D-glucopyranosyl)-(1----2)-3,4,6- tri-O- benzyl-alpha-D-mannopyranoside (11) by use of a few reaction steps. The 4(3)-hydroxyl group of 11 was methanesulfonylated, and the product subjected to SN2 replacement with acetate anion, to give the D-galactosamine-containing trisaccharide derivative (12). After basic hydrolysis of 12, the 4(3)-hydroxyl group was sulfated, and all benzyl groups were removed by hydrogenolysis, giving methyl O-(2-acetamido-2-deoxy-4-O-sulfo-beta-D-galactopyranosyl)-(1----4)-O-(2- acetamido-2-deoxy-beta-D-glucopyranosyl)-(1----2)-alpha-D-mannopyranosid e monosodium salt, the methyl alpha-glycoside derivative of the peripheral trisaccharide sequence of the pituitary glycoprotein hormone lutropin.
authors.affiliation: RIKEN (The Institute of Physical and Chemical Research), Saitama, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Nishimura
authors.forename: H
authors.initials: H
authors.lastname: Kuzuhara
mesh_terms: D002240:Carbohydrate Sequence; D004187:Disaccharides; D005936:Glucans; D007986:Luteinizing Hormone / Q000737:chemistry*; D008722:Methods; D008969:Molecular Sequence Data; D015394:Molecular Structure; D014312:Trisaccharides / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D004187:Disaccharides; D005936:Glucans; D014312:Trisaccharides; C032438:chitobiose; D007986:Luteinizing Hormone