Electron ionization mass spectrometric study of monomeric models of O‐polysaccharides of Vibrio cholerae O:1, serotypes Ogawa and Inaba

Abstract

Fragmentation mechanisms of electron ionization (EI) mass spectrometry of the title compounds have been elucidated by high-resolution (HR) mass spectrometric measurements of the elemental composition and measurements of the metastable transitions (B(2)/E, CID). The experimental results were interpreted with the help of Mass Frontier 3.0 software, which aided the elucidation of fragmentation mechanisms and helped to deduce structures of the ions formed. Characteristic under the conditions of EI-MS measurement was the production of protonated adducts. Three distinct pathways observed include the formation of oxonium type ions, the conjugated transfer of electrons in the pyranose ring, and cleavage of the acylamide side chains. By applying the results obtained, the molecular mass, as well as the structures of both the saccharide and acylamide side chain involved in related substances, can be determined.

Positive electrospray ion trap multistage mass spectrometric fragmentation of synthetic analogs of saccharide part of lipopolysaccharides of Vibrio cholerae O:1

“…The final energies were obtained using the single point calculations at the B3LYP/6-311 ϩϩ G** levels from the 6-31G* optimized geometry. Mass Frontier software [15] 4.0 (MF) was used to assist in the elucidation the fragmentation [16].…”

“…Similarly, the af 4 , cf 4 , df4 , and ff 4 species are visible in the MS 3 fragmentation of f 4 ions. In the spectrum of the Ogawa pentamer 5 Og(Figure 5), the secondary ions da 5 and fa5 ions are visible at the MS 3 fragmentation of a 5 species, and ac 5 , cc 5 , dc 5, ec 5 , and fc 5 are present in the fragmentation of c 5 product ions.…”

“…This work was carried out within studies of antigenic determinants of lipopolysaccharides (LPS) of Vibrio cholerae O:1. Previously, the monomeric models were studied by electron ionization mass spectrometry [5]. Here, we study synthetic mono-to hexasaccharides (Figure 1) that mimic the fragments of the O-antigen of Ogawa and Inaba O-PS by electrospray mass spectrometry [6] in …”

Negative Matrix-Assisted Laser Desorption/Ionization Time-of-Flight/Time-of-Flight Tandem Mass Spectrometry Fragmentation of Synthetic Analogs of the O-Specific Polysaccharide of Vibrio Cholerae O:1 in the Presence of Anionic Dopants

“…Previously, monomeric models were studied by electron ionization mass spectrometry. 8 More recently, we studied synthetic mono-to hexasaccharides that mimic the fragments of O-PS by electrospray multistage ion trap mass spectrometry in the positive mode. 9 The main feature of this fragmentation is the step-by-step shortening of the length of oligosaccharides.…”

Negative Electrospray, Ion Trap Multistage Mass Spectrometry of Synthetic Fragments of the O-PS of Vibrio Cholerae O:1

“…Previously, the monomeric models have been studied by electron ionization (ESI) mass spectrometry (MS). 1,2 In continuation of the study, fragmentation of �M + Na� + positive ions, obtained by electrospray multistage ion trap mass spectrometry (ESI IT MS n , n �� 1-3) was elucidated. 3 Recent work suggests that fragmentation of negative ions of carbohydrates gives complementary information with, in many cases, [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] additional fragmentation that can reveal finer details of the structure.…”