Sequence Ion Structures and Dissociation Chemistry of Deprotonated Sucrose Anions

• Published in: Journal of the American Society for Mass Spectrometry Vol. 29; no. 12; pp. 2380 - 2393
• Main Authors: Bythell, Benjamin J., Rabus, Jordan M., Wagoner, Ashley R., Abutokaikah, Maha T., Maître, Philippe
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2018; Springer Nature B.V; American Chemical Society
• Subjects: ABSORPTION SPECTROSCOPY; Analytical Chemistry; Anions; Banded structure; Bioinformatics; Biotechnology; CARBOHYDRATES; Carbon; Carbonyls; Chemical Sciences; Chemistry; Chemistry and Materials Science; COLLISIONS; COMPARATIVE EVALUATIONS; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DENSITY FUNCTIONAL METHOD; Density functional theory; Diagnostic systems; DISSOCIATION; FORECASTING; FRAGMENTATION; GLUCOSE; INFRARED SPECTRA; Ions; Mass spectrometry; MASS SPECTROSCOPY; Organic Chemistry; Proteomics; Research Article; SACCHAROSE; Sucrose; Carbohydrates; Density functional theory; IRMPD; Collision-induced dissociation
• ISSN: 1044-0305; 1879-1123
• DOI: 10.1007/s13361-018-2065-0

We investigate the tandem mass spectrometry of regiospecifically labeled, deprotonated sucrose analytes. We utilize density functional theory calculations to model the pertinent gas-phase fragmentation chemistry of the prevalent glycosidic bond cleavages ( B 1 -Y 1 and C 1 -Z 1 reactions) and compare these predictions to infrared spectroscopy experiments on the resulting B 1 and C 1 product anions. For the C 1 anions, barriers to interconversion of the pyranose [α-glucose-H] − , C 1 anions to entropically favorable ring-open aldehyde-terminated forms were modest (41 kJ mol −1 ) consistent with the observation of a band assigned to a carbonyl stretch at ~ 1680–1720 cm −1 . For the B 1 anions, our transition structure calculations predict the presence of both deprotonated 1,6-anhydroglucose and carbon 2-ketone ((4S,5S,6R)-4,5-dihydroxy-6-(hydroxymethyl)dihydro-2H-pyran-3(4H)-one) anion structures, with the latter predominating. This hypothesis is supported by our spectroscopic data which show diagnostic bands at 1600, 1674, and 1699 cm −1 (deprotonated carbon 2-ketone structures), and at ~ 1541 cm −1 (both types of structure) and RRKM rate calculations. The deprotonated carbon 2-ketone structures are also the lowest energy product B 1 anions. Graphical Abstract ᅟ