Complete 1H and 13C NMR assignment of mono-sulfated galactosylceramides with four types of ceramides from human kidney

The full assignment of H-1 and C-13 NMR signals of galactosylceramide 3-sulfate (galactosyl sulfatide) and H-1 signals of galactosyIleramide 6-sulfate was achieved by using H-1-H-1 DQF-COSY and H-1-C-13 heteronuclear COSY. Analyses were performed on a mixture of galactosyl sulfatides with four representative ceramide types consisting of a combination of non-hydroxy or 2-hydroxy fatty acids and sphingenine or 4D-hydroxysphinganine (trihydroxysphinganine) as the long-chain bases. The H-1 and C-13 NMR parameters of galactosyl sulfatide with 4-hydroxysphinganine as well as C-13 signals of complex lipids with 4-hydroxysphinganine were elucidated for the first time. Not only sulfation of the galactosyl residue, but also modification of the aglycon, including hydroxylation of fatty acids and hydration of the double bond in sphingoid bases, altered the chemical shifts substantially. In addition, the unique long-range coupling constants, (4)J(H,H) and (5)J(H,H), in the galactosyl residue of galactosyl sulfatide could be determined. (C) 2000 Elsevier Science Ltd. All rights reserved.