Differentiation of Methyl-glucopyranoside Anomers by Infrared Multiple Photon Dissociation with a Tunable CO₂ Laser

Abstract

Fragmentation of lithium cation-attached alpha- and beta-O-methyl-glucopyranoside precursor ions, formed by electrospray ionization (ESI) and trapped in a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer, was produced by infrared radiation from a tunable CO(2) laser. Irradiation over the wavelength range from 9.20 to 10.80 microm yielded unique fragmentation patterns that were a function of both product ion mass and laser wavelength. Comparison of the relative percent abundances of fragment ions for the two anomers revealed statistically significant differences for wavelengths between 9.20 and 9.70 microm at the 95% confidence level. On the basis of these results, differentiation of anomeric configurations of monosaccharides within oligosaccharides may be possible to address by wavelength-selective infrared multiple-photon dissociation (IRMPD).

Structural Characterization of Carbohydrates by Fourier Transform Tandem Mass Spectrometry

“…Typically, a 10.6 μm CO 2 laser is used for infrared irradiation, but tunable CO 2 laser IRMPD was recently implemented [112–114]. The latter approach was able to differentiate anomers of lithium-adducted methyl-glucopyranoside by comparing relative product ion abundances as function of laser wavelength [113]. Differentiation of lithium-tagged glucose-containing disaccharides was previously reported by Polfer et al with 7–11 μm photons from a free electron laser [115].…”

“…During IR activation, multiple photons are absorbed and the corresponding energy is redistributed over all precursor ion vibrational modes [113]. Therefore, multiple fragmentation events may take place.…”

Linkage and Anomeric Differentiation in Trisaccharides by Sequential Fragmentation and Variable-Wavelength Infrared Photodissociation

“…A key limitation of mass spectrometry, however, is its inability to distinguish isomers based on mass information alone. Strategies for distinguishing isomers have, thus, focused on distinguishing other physical properties [9], such as the collision cross sections of ions, as measured in ion mobility [10][11][12][13][14][15][16][17] experiments, or their fragmentation patterns in collision-induced dissociation (CID) [18][19][20][21][22][23], electron-mediated dissociation [24][25][26], or laser photodissociation [27][28][29][30][31][32][33][34][35][36].…”

“…Metal-adducted complexes have been shown to exhibit advantages based on higher ionization efficiencies and more informative fragmentation [14,20,39]. For alkali metal adducts, it has been shown that Li + is bound tightest and causes most abundant cross-ring fragmentation [33,40], rationalizing the prevalent use of lithiated oligosaccharides in positive-mode oligosaccharides MS analysis [18,19,29,30,34,41]. For the negative-mode MS analysis, previous studies have shown that Cl -adducts are highly stable and yield high abundances of fragment ions [42][43][44][45].…”

Study of fragmentation pathways of lithiated α,β‐unsaturated thioesters by electrospray ionization mass spectrometry

“…The mass spectrometric behavior of lithiated molecules has attracted increasing attention because of their interesting fragmentation pathways. Recent reports on the mass spectrometric fragmentation of lithiated molecules related to polymer,1, 2 oligosaccharide,3 disaccharides,4 acylglycerols,5 glucopyranosides,6 glycerophospholipids,7 saponins,8 esters,9 lipids,10 fatty acids,11 deoxydinucleotides12 and peptides 13, 14…”