Structures of novel acidic galactooligosaccharides synthesized by Bacillus circulans beta-galactosidase

The structures of acidic oligosaccharides synthesized by a transglycosylation reaction by Bacillus circulans beta-galactosidase, using lactose as the galactosyl donor, and N-acetylneuraminic acid (NeuAc) and glucuronic acid (GlcUA) as the acceptors were investigated. Acidic oligosaccharides thus synthesized were purified by anion exchange chromatography and charcoal chromatography. The MS and NMR studies indicated that the acidic oligosaccharides from NeuAc were Gal beta-(1-->8)-NeuAc, Gal beta-(1-->9)-NeuAc, and Gal beta-(1-->3)-Gal beta-(1-->8)-NeuAc, and those from GlcUA were Gal beta-(1-->3)-GlcUA and Gal beta-(1-->4)-Gal beta-(1-->3)-GlcUA. These are novel acidic galactooligosaccharides.