title: Assignment of acetyl groups to O-2 and/or O-3 of pectic oligogalacturonides using negative electrospray ionization ion trap mass spectrometry.
abstract: Partially acetylated and methylated oligogalacturonides produced by enzymatic hydrolysis of sugar beet pectin were analysed by negative electrospray ionization ion trap mass spectrometry (ESI-ITMS). The (18)O labelling of the oligomer reducing end allowed the precise assignment of the fragments resulting from glycosidic bond and cross-ring cleavages. The collisional-induced dissociation of the C(i) and Z(j) fragment ions through sequential MS(n) experiments always displayed (0, 2)A-type cross-ring cleavage ions which were related to C(2)H(4)O(2) losses. These (0, 2)A ions appeared to be highly diagnostic ions allowing the precise location of the acetyl groups to the O-2 and/or O-3 of the acetylated galacturonic acid residues.
authors.affiliation: Institut National de la Recherche Agronomique, Unité de Recherche sur les Polysaccharides, leurs Organisations et Interactions, rue de la Géraudière, BP 71627, 44316 Nantes, France. quemener@nantes.inra.fr
authors.forename: Bernard
authors.initials: B
authors.lastname: Quéméner
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Cabrera Pino
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Ralet
authors.forename: Estelle
authors.initials: E
authors.lastname: Bonnin
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Thibault
mesh_terms: D000107:Acetylation; D027461:Beta vulgaris / Q000737:chemistry; D002240:Carbohydrate Sequence; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis* / Q000737:chemistry*; D010368:Pectins / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D009844:Oligosaccharides; C412763:oligogalacturonic acid; D010368:Pectins