PROTON NUCLEAR MAGNETIC-RESONANCE ANALYSIS OF ANOMERIC STRUCTURE OF GLYCOSPHINGOLIPIDS - BLOOD-GROUP ABH-ACTIVE SUBSTANCES

High resolution NMR spectra of permethylated and permethylated-reduced (LiAlH4) derivatives were recorded in chloroform solution for the following glycosphingolipids with known structure: lactotriaosylceramide, neolactotetraosylceramide (paragloboside), 2 [human] blood group H-active pentaglycosylceramides (type 1 and type 2 saccharide chains, respectively), a B-active hexaglycosylceramide, an A-active hexaglycosylceramide and an A-active octaglycosylceramide. Good quality and resolution allow a clear-cut diagnosis of .alpha.-anomeric protons of Fuc, Gal, and GalNAc, and in most cases of all .beta. protons. Upon reduction there is a strong deshielding effect on H-1 of Gal of Gal.beta.1 .fwdarw. 3GlcNAc but not on Gal of Gal.beta.1 .fwdarw. 4GlcNAc. Type 1 and type 2 chains can be differentiated by this method, a structural difference of importance for serological specificity. NMR spectroscopy may provide conclusive information on the anomeric structure of the immunodeterminant of blood group-active glycolipids using the same derivatives as for sequence analysis by mass spectrometry.