title: Electrospray ionization ion-trap multistage mass spectrometric study of sodium cationized aldobiuronic and pseudoaldobiuronic acid derivatives.
abstract: Fragmentation mechanisms of electrospray ionization (ESI) mass spectrometry of aldobiuronic and pseudoaldobiuronic acid derivatives were elucidated by multistage mass spectrometric (MS(n), n = 2-5) measurements of selected ions. Characteristic under the conditions of ESI-MS analysis is the production of alkali metal (Na and K) cationized adducts. The probability the of locations of Na cations in per-O-methylated compounds was proved by quantum chemical calculations, using the Jaguar program. The most probably position of alkali metal attachment is the carboxy group of the methoxycarbonyl C-5 group of the uronic acid unit. Characteristic cleavages vary according the kind of O-derivatization. In most cases they take place on the acidic part of the dimer and at the interglycosidic oxygen atom. As a result, the criteria for the differentiation of aldobiouronic and pseudoaldobiouronic acids derivatives were elucidated.
authors.affiliation: Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 84258 Bratislava, Slovakia.
authors.forename: Vladimír
authors.initials: V
authors.lastname: Kovácik
authors.forename: Slávka
authors.initials: S
authors.lastname: Bekesová
authors.forename: Igor
authors.initials: I
authors.lastname: Tvaroska
authors.forename: Ján
authors.initials: J
authors.lastname: Hirsch
authors.forename: Josef
authors.initials: J
authors.lastname: Chmelík
mesh_terms: D002236:Carbohydrate Conformation; D004187:Disaccharides / Q000737:chemistry*; D007202:Indicators and Reagents; D011134:Polysaccharides / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D014574:Uronic Acids / Q000737:chemistry*
chemical_list: D004187:Disaccharides; D007202:Indicators and Reagents; D011134:Polysaccharides; D014574:Uronic Acids