Isolation and structural characterization of five oligosaccharide alpha1-phosphates and one sulfated glycopeptide...

Five oligosaccharide alpha1-phosphates and one sulfated glycopeptide have been isolated from the hemofiltrate of one patient with end-stage renal disease. Isolation of these compounds has been achieved using reverse osmosis, ion-exchange and size-exclusion chromatography and high performance liquid chromatography. The structures were predominantly elucidated by one- and two-dimensional 1H and 31P NMR spectroscopy. The chemical structures were determined to be: 1 NeuAc alpha2-3Gal alpha1-OPO3H2; 2 NeuAc alpha2-6Galbeta1-4GlcNAc alpha1-OPO3H2; 3 NeuAc alpha2-3Galbeta1-3GalNAc alpha1-OPO3H2; 4 NeuAc alpha2-3Galbeta1-3[NeuAc alpha2-6]GalNAc alpha1-OPO3H2 (proposed structure); 5 Fuc alpha1-2Galbeta1-4[Fuc alpha1-3]GlcNAc alpha1-OPO3H2; 6 HOSO3-4Fuc alpha1-6GlcNAcbeta1-NAsn. While 2 and 3 have been previously characterized as compounds of urine and hemofiltrate, the oligosaccharide alpha1-phosphates 1, 4, and 5 could be isolated--to our knowledge--for the first time from biological material. Compound 6 is the first glycopeptide reported to contain a 4-sulfated fucose residue.