E.I. and C.I. mass-spectral identification of some derivatives of 7-O-(2-amino-2-deoxy-α-d-glucopyranosyl)-l-glycero-d-manno-heptose, obtained from lipopolysaccharides representative of the Vibrionaceae family

✍ Scribed by Joseph H. Banoub; Francis Michon; Derek H. Shaw; René Roy

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 735 KB
• Volume: 128
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(84)85330-6

✦ Synopsis

The electron-impact (e.i.) and chemical-ionization (ci.) mass spectra of the 2-di-N-methyl (2) 2-N-acetyl (3), and 2-(N-acetyl)-N-methyl (4) derivatives of 1,5-di-O-acetyl-7-O-(2-amino-2-deoxy-3,4,6-tri-O-methyl-~-D-glucopyranosyl)-2,3,4,6-tetra-O-methyl-L-glycero-D-manno-heptitol, obtained from the methylation analysis of the core oligosaccharides of Aeromonus hydrophilu Chemotypes I and II, are described and their fragmentation patterns proposed. The e.i.-mass spectrum of the 2-dimethylamino derivative 2 showed the primary fragment ion Ai, characteristic of the glycosyl group of this glycosylalditol, whereas the mass spectra of the 2-acetamido (3) and 2-(N-methylacetamido) derivatives (4) gave the respective primary ions, Al-fragments, and aid+-fragments diagnostic of the glycosyl group and the alditol residue of the respective glycosylalditol. The c.i.-mass spectra of the glycosylalditol derivatives 2,3, and 4 gave, as major peaks, the protonated molecular ion [MH]+, together with the primary fragment ion A, characteristic of the glycosyl group of the respective derivatives. The e.i.-and c.i.-mass spectra and fragmentation pattern of methyl 7-O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-cw-D-glucopyranosyl)-2,3,4,6-tetra-O-acetyl-L-gfycero-~-D-munno-heptopyranoside (6) are also reported.