Typing of core and backbone domains of mucin-type oligosaccharides from human ovarian-cyst glycoproteins by 500-MHz 1H-NMR spectroscopy

Abstract

Human blood‐group A active glycoproteins from ovarian‐cyst fluid were subjected to Smith degradation and subsequent β‐elimination. The resulting oligosaccharide‐alditols represent the core and backbone domains of the O‐linked carbohydrate chains. Nine of these, ranging in size from disaccharides to hexasaccharides, were investigated by ¹H‐NMR spectroscopy. Their primary structures could be adequately characterized. In particular, the core types, i.e. the substitution patterns of N‐acetylgalactosaminitol (GalNAc‐ol) as well as the types of backbone, i.e. the linkage types of alternating Gal‐GlcNAc sequences, were unambiguously identified. The core type GlcNAcβ(1–3)GalNAc‐ol is described for the first time as occurring in ovarian‐cyst glycoprotein.