title: Oxidation of mannosyl oligosaccharides by hydroxyl radicals as assessed by electrospray mass spectrometry.
abstract: The hydroxyl radicals are widely implicated in oxidation of carbohydrates during biological and industrial processes being responsible for their structural modifications and causing functional damage. The identification of intermediate oxidation products is hampered by a lack of reliable sensible methods for their detection. In this study, the oxidation of two models of galactomannans (Man(3) and GalMan(2)) has been studied in reaction with hydroxyl radical generated by Fenton reaction. The oxidation patterns were assessed using preparative ligand-exchange/size-exclusion chromatography (LEX/SEC) coupled with tandem electrospray mass spectrometry (ESI-MS/MS). This allowed the identification of derived oligosaccharides (OS) containing hexuronic, hexonic, pentonic and erythronic acid residues and neutral OS bearing hydroperoxy, hydrated carbonyl moieties and residues from pyranosyl ring cleavage. The depolymerization products have been also detected upon oxidation of oligomers. This study allowed developing a simple, effective 'fingerprinting' protocol for detecting the damage done to mannans by oxidative radicals.
authors: Mass Spectrometry Centre, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors: Joana
authors: J
authors: Tudella
authors: Fernando M
authors: FM
authors: Nunes
authors: Rosa
authors: R
authors: Paradela
authors: Dmitry V
authors: DV
authors: Evtuguin
authors: Pedro
authors: P
authors: Domingues
authors: Francisco
authors: F
authors: Amado
authors: Manuel A
authors: MA
authors: Coimbra
authors: Ana I R N A
authors: AI
authors: Barros
authors: M Rosario M
authors: MR
authors: Domingues
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D002240:Carbohydrate Sequence; D002850:Chromatography, Gel; D004187:Disaccharides / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry; D008351:Mannans / Q000737:chemistry*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D014312:Trisaccharides / Q000737:chemistry*; D014574:Uronic Acids / Q000737:chemistry
chemical_list: D000447:Aldehydes; D004187:Disaccharides; D007659:Ketones; D008351:Mannans; D010545:Peroxides; D014312:Trisaccharides; D014574:Uronic Acids; D017665:Hydroxyl Radical