Dissociation mechanisms for metal N-glycosides of N-acetyl neuraminic acid

Metal(II) N-glycoside complexes of N-acetyl neuraminic acid are synthesized and analyzed by electrospray ionization ion trap mass spectrometry. The di ssociation products For various ligands (1,3-diaminopropane and diethylenet riamine) and metals (Co, Ni. Cu, Zn) are compared and contrasted. Most nota ble were the differences in the cross-ring cleavages: the X-0.4 cross-ring cleavage seems to be favored by the 1,3-diaminopropane ligand, whereas the X-0.2, X-0.4-H2O, and X-0.4 cross-ring cleavages are prevalent in the dieth ylenetriamine ligand complexes. Dissociation mechanisms are postulated base d on the results of H-2 and C-13 labeling experiments. (C) 2001 Elsevier Sc ience B.V.