Isolation of unusually composed sialyl-compounds from hemofiltrate

Sialyl compounds are essential components of various biological fluids but relatively little is known about their occurrence in the extracellular fluid of patients with end-stage renal disease. As we have developed a macropreparative method for concentrating and desalting a wide range of fractions from diluted biological fluids we have been able to isolate and identify 5 sialooligosaccharides, 3 sialosugarphosphates, 2 monosialoglycopeptides and 1 disialoglycopeptide. The structures have been elucidated predominantly by one and two-dimensional NMR spectroscopy, enzymatic degradation and FAB mass spectrometry. The accumulation of these compounds in uremic sera may be of particular interest as they may interact in the molecular biology of diseases typically associated with the uremic state, e.g., immune deficiency, neurological disorders, receptor binding abnormalities, complement system disturbances and cell membrane alterations.