Carbohydrate purification using ultrafiltration, reverse osmosis and nanofiltration

Abstract

The invention provides methods for purifying carbohydrates, including oligosaccharides, nucleotide sugars, and related compounds, by use of ultrafiltration, nanofiltration and/or reverse osmosis. The carbohydrates are purified away from undesired contaminants such as compounds present in reaction mixtures following enzymatic synthesis or degradation of oligosaccharides.

1 .- 30 . (canceled)  
     
     
         31 . A method of removing an unsialylated carbohydrate contaminant from a mixture comprising said contaminant and a sialyl galactoside which is a member selected from sialyl lactosides; glycolipids; liposaccharides; 
 NeuAcα2,3 Galβ1,4(Fucα1,3)GlcNAcβ1,4Gal-OEt;    NeuAcα2,3Galβ1,4(Fucα1,3)GlcNAcβ1,4Galβ1-OEt; and    NeuAcα2,3Galβ1,3-Y, in which Y is a saccharide or an oligosaccharide, said method comprising, contacting said mixture with a nanofiltration or reverse osmosis membrane at a pH of from about 1 to about 7, for a length of time sufficient to allow said unsialylated carbohydrate contaminant to pass through said membrane.