title: Patterns of methyl and O-acetyl esterification in spinach pectins: new complexity.
abstract: Driselase-digestion of cell walls from suspension-cultures of spinach (Spinacia oleracea L.), followed by anion-exchange chromatography, gel-permeation chromatography, preparative paper chromatography and preparative paper electrophoresis, yielded ten uronic acid-containing products in addition to free galacturonic acid (GalA). These included 4-O-methylglucuronic acid, alpha-L-rhamnopyranosyl-(1-->4)-D-glucuronic acid and several oligosaccharides containing GalA residues. The structures were unambiguously determined by a combination of 1- and 2-dimensional NMR spectroscopic techniques. Five of the six homogalacturonan-derived oligosaccharides purified contained 3-O-acetyl-GalA residues; however, methyl-esterified GalA residues occurred adjacent to both 2-O-acetyl-GalA and 3-O-acetyl-GalA residues. An acetylated, rhamnogalacturonan-I-derived oligosaccharide that was purified also contained 3-O-acetyl-GalA residues. Taken together with published data, our findings indicate considerable diversity in the patterns of pectin esterification. The implications for the action of pectin esterases are discussed.
authors: The Edinburgh Cell Wall Group, Institute of Cell and Molecular Biology, The University of Edinburgh, UK.
authors: Paola
authors: P
authors: Perrone
authors: Chandralal M
authors: CM
authors: Hewage
authors: Adam R
authors: AR
authors: Thomson
authors: Kevin
authors: K
authors: Bailey
authors: Ian H
authors: IH
authors: Sadler
authors: Stephen C
authors: SC
authors: Fry
mesh_terms: D002473:Cell Wall / Q000737:chemistry; D002845:Chromatography; D004951:Esterification; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000032:analysis / Q000737:chemistry; D010368:Pectins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D018724:Spinacia oleracea / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*
chemical_list: D009844:Oligosaccharides; D010368:Pectins