Storage of sialic acid-containing carbohydrates in the placenta of a human galactosialidosis fetus. Isolation and structural characterization of 16 sialyloligosaccharides

Abstract

From the placenta of a human fetus with galactosialidosis, detected by prenatal diagnosis, sialyloligosaccharides were isolated by successively gel-permeation chromatography on Bio-Gel P-6, anion-exchange chromatography on Mono Q and high-performance liquid chromatography on Lichrosorb-NH2. 16 sialic acid-containing N-glycosidic N-acetyllactosamine type of structures were identified by sugar analysis and 500-MHz 1H-NMR spectroscopy. The fully sialylated oligosaccharides differ from each other in the type of branching (mono-, di-, tri-, tri'-, and tetra-antennary) or sialic acid linkage types (alpha2-3/alpha2-6). The isolated carbohydrates, including six novel structures, can be presented as follows (the numerals in a column represent one compound).