Logically derived sequence tandem mass spectrometry for structural determination of Galactose oligosaccharides

Calendula arvensis (Vaill.) L.: A Systematic Plant Analysis of the Polar Extracts from Its Organs by UHPLC-HRMS

“…The TOF-MS/MS spectrum highlighted the neutral loss of 162.05 Da, attributed to the (hexose-H 2 O) residue, to form the fragment ion at m/z 957.5162 by ester bond cleavage at C-28 (Figure S4). A cross ring cleavage of saccharidic moiety and the loss of 120 Da supplied the ion at m/z 837.4726, suggesting a 1-2 bond between the units [66], whereas, through the further loss of 162.05 Da, the ion at m/z 795.4604 was generated. The latter, attributed to a hexosyl-saponin, underwent H 2 O loss to achieve the ion at m/z 777.4502, and a concerted loss of (44 + 18) Da to provide the ion at m/z 633.4058, which, through further H 2 O loss, gave the ion at m/z 615.3949, while the loss of 162.05 Da generated the fragment ion at m/z 471.3505, due to the deprotonated aglycone, tentatively identified as echinocystic acid.…”

Collision-induced dissociation of Na+-tagged ketohexoses: experimental and computational studies on fructose

“…26 It has recently been demonstrated that the structural information of oligosaccharides, including stereoisomerism, anomeric configuration, and linkage positions, can be obtained by the so-called logically derived sequence (LODES) tandem mass spectrometry (MS n ) approach. [27][28][29][30][31][32] To correctly interpret the MS results, it is helpful to understand the mechanisms of the different monosaccharides. Along this direction, several mechanistic studies on selected Na +tagged (aldo-)hexoses [33][34][35] and their derivatives 36,37 have been carried out with an integrated approach combining experimental and theoretical analysis.…”

Identifying Mixtures of Isomeric Human Milk Oligosaccharides by the Decomposition of IR Spectral Fingerprints

“…While the speed and sensitivity of mass spectrometry (MS) make it ideal for most forms of biomolecular analysis, it is impossible for single-stage MS alone to distinguish between isomers. Tandem MS, most frequently using collision-induced dissociation (CID), can identify many isomeric glycans by their fragmentation patterns, − however, it often has difficulty in distinguishing between the most subtly different isomeric forms. These limitations can be partially overcome by the addition of an orthogonal technique, such as ion mobility spectrometry (IMS), which separates gas-phase ions based on their collisional cross section (CCS). − Recent developments in IMS methods, such as trapped ion mobility spectrometry (TIMS), cyclic IMS (cIMS), and structures for lossless ion manipulation (SLIM), , offer significantly higher resolution than standard drift-tube IMS in many cases, enabling the separation of glycan isomers. − While combining high-resolution IMS with tandem MS helps reduce the problem, the highly complex mobility profiles often leave isomer identification ambiguous …”