title: Synthesis of apiose-containing oligosaccharide fragments of the plant cell wall: fragments of rhamnogalacturonan-II side chains A and B, and apiogalacturonan.
abstract: Fragments of pectic polysaccharides rhamnogalacturonan-II (RG-II) and apiogalacturonan were synthesised using p-tolylthio apiofuranoside derivatives as key building blocks. Apiofuranose thioglycosides can be conveniently prepared by cyclization of the corresponding dithioacetals possessing a 2,3-O-isopropylidene group, which is required for preservation of the correct (3R) configuration of the apiofuranose ring. The remarkable stability of this protecting group in apiofuranose derivatives requires its replacement with a more reactive protecting group, such as a benzylidene acetal which was used in the synthesis of trisaccharide β-Rhap-(1→3')-β-Apif-(1→2)-α-GalAp-OMe. The X-ray crystal structure of the protected precursor of this trisaccharide has been elucidated.
authors.affiliation: Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, UK NR4 7UH. sergey.nepogodiev@bbsrc.ac.uk
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Nepogodiev
authors.forename: Margherita
authors.initials: M
authors.lastname: Fais
authors.forename: David L
authors.initials: DL
authors.lastname: Hughes
authors.forename: Robert A
authors.initials: RA
authors.lastname: Field
mesh_terms: D029064:Araceae / Q000737:chemistry* / Q000166:cytology; D002236:Carbohydrate Conformation; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D010368:Pectins / Q000138:chemical synthesis* / Q000737:chemistry; D010429:Pentoses / Q000737:chemistry*; D035962:Zosteraceae / Q000737:chemistry* / Q000166:cytology
chemical_list: D010429:Pentoses; C042492:rhamnogalacturonan II; D010368:Pectins; C004983:apiose