title: Synthesis of glycopeptides with phytoalexin elicitor activity--III. Syntheses of hexaglycosyl hexapeptides and a nonaglycosyl hexapeptide.
abstract: A block synthesis of the model compound for the phytoalexin elicitor-active glycoprotein is described. Combination of the C-terminus free compounds, N-(9-fluorenylmethoxycarbonyl)-O-(tert-butyl)-L-seryl-L-proline (1) or N-(9-fluorenylmethoxycarbonyl)-(2,3,4,6-tetra-O-acetyl-beta-D-g luc opyranosyl) -(1-->6)-(2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl)-(1-->6) -(2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl)-L-seryl-L-proline (2) with the N-terminus free compounds, 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl -(1-->6)-(2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl)-(1-->6)-(2,3,4-tri- O -acetyl-alpha-D-mannopyranosyl)-L-seryl-L-prolyl-L-seryl-L-proline methyl ester (4), O-(tert-butyl)-L-seryl-L-prolyl-(2,3,4,6-tetra-O-acetyl-beta-D -glucopyranosyl)-(1-->6)-(2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl) -(1-->6)-(2,3,4-tri-O-acetyl- alpha-D-mannopyranosyl)-L-seryl-L-proline methyl ester (6) or 2,3,4,6-tetra-O-acetyl-beta-D- glucopyranosyl -(1-->6)-(2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl)-(1-->6) -(2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl)-L-seryl-L-prolyl -(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-(1-->6) -(2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl)-(1-->6) -(2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl)-L-seryl-L-proline methyl ester (8), by use of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) gave three hexaglycosyl hexapeptides and a nonaglycosyl hexapeptide derivatives (9, 11, 14, and 17). These N-terminus free compounds were derived from triglycosyl tetrapeptides (3 and 5) or a hexaglycosyl tetrapeptide (7) on selective deblock reaction by morpholine. The hexaglycosyl hexapeptides (10, 13, and 16) and the nonaglycosyl hexapeptide (18) have been prepared by the convergent block synthesis.
authors.affiliation: Kyoritsu College of Pharmacy, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takeda
authors.forename: T
authors.initials: T
authors.lastname: Kanemitsu
authors.forename: Y
authors.initials: Y
authors.lastname: Ogihara
mesh_terms: D002240:Carbohydrate Sequence; D006020:Glycopeptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000494:pharmacology; D010936:Plant Extracts / Q000096:biosynthesis*; D012717:Sesquiterpenes; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013729:Terpenes; D000094162:Phytoalexins
chemical_list: D006020:Glycopeptides; D009842:Oligopeptides; D010936:Plant Extracts; D012717:Sesquiterpenes; D013729:Terpenes; D000094162:Phytoalexins