α-D-Glcp-(1↔1)-β-D-Galp-containing oligosaccharides, novel products from lactose by the action of β-galactosidase

Abstract

A mixture of oligosaccharides produced by beta-galactosidase using lactose as a substrate was fractionated according to degree of polymerization using gel filtration, followed by high-pH anion-exchange chromatography. The fractions obtained were analyzed using monosaccharide analysis, methylation analysis, mass spectrometry, and NMR spectroscopy. Twelve novel non-reducing oligosaccharides were characterized, namely, [beta-D-Galp-(1->4)]n-alpha-D-Glcp-(1<->1)-beta-D-Galp[-(4<-1)-beta-D-Galp]m, with n, m=(1, 2, 3, or 4) and beta-D-Galp-(1->2)-alpha-D-Glcp-(1<->1)-beta-D-Galp.