Lactones of disialyl lactose: characterisation by NMR and mass spectra.
The lactonisation of alpha-Neup5Ac-(2-->8)-alpha-Neup5Ac-(2-->3)-beta-D-Galp-(1-->4)-D-Glc (disialyl lactose) was investigated. (1)H and (13)C NMR chemical shifts of disialyl lactose and alpha-Neup5Ac-(2-->8, 1-->9)-alpha-Neup5Ac-(2-->3, 1-->2)-beta-D-Galp-(1-->4)-D-Glc (disialyl lactose-dilactone) were assigned bas