title: Identification of anomeric configuration of underivatized reducing glucopyranosyl-glucose disaccharides by tandem mass spectrometry and multivariate analysis.
abstract: The possibility of discrimination of the anomeric configuration (alpha or beta) of underivatized reducing glucopyranosyl-glucose disaccharides, using a hybrid mass spectrometer Q-TOF 2 (Micromass), a linear ion trap LXQ (Thermo), and a triple quadrupole Quattro (Micromass) with an electrospray source (ESI) was investigated. Differences observed in the relative abundances of specific product ions obtained from collisionally induced dissociation of the [M + Li]+ adducts were statistically analyzed, and discriminant analysis was performed. MANOVA has shown that anomeric configuration has influence on the combined dependent variables (relative abundances of m/z product ions) in all the three mass spectrometers used (Q-TOF 2, LIT, and QqQ). Discriminant analysis has shown that, in all instruments, it is possible to discriminate anomeric configurations and to build a diagnostic model. These diagnostic differences are even more relevant considering that no derivatization procedures are needed for obtaining this structural information. The Q-TOF 2 instrument has been shown to give data that allowed us to build a model with better discriminant power (Wilks' lambda value of 0.014) followed by the QqQ instrument (Wilks' lambda value of 0.029) and the LIT instrument (Wilks' lambda value of 0.037).
authors.affiliation: Department of Chemistry, University of Aveiro, P-3810-193 Aveiro, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Simões
authors.forename: Pedro
authors.initials: P
authors.lastname: Domingues
authors.forename: Ana
authors.initials: A
authors.lastname: Reis
authors.forename: Fernando M
authors.initials: FM
authors.lastname: Nunes
authors.forename: Manuel A
authors.initials: MA
authors.lastname: Coimbra
authors.forename: M Rosario M
authors.initials: MR
authors.lastname: Domingues
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000032:analysis / Q000737:chemistry*; D005947:Glucose / Q000031:analogs & derivatives* / Q000032:analysis; D007477:Ions / Q000737:chemistry; D008969:Molecular Sequence Data; D015999:Multivariate Analysis; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D004187:Disaccharides; D007477:Ions; D005947:Glucose