Elucidation of glycosidic linkages, configuration/conformation in oligosaccharide ‘Bubliose’ from buffalo colostrum by 2-D NMR and mass spectrometry

Milk oligosaccharides exhibit potent biological activities such as anti-tumour, immunological, anti-complimentary, anti-cancer, anti-inflammatory, hypoglycaemic and antiviral activities. Buffalo milk oligosaccharide induces significant stimulation of antibody, delayed type hypersensitivity and non-specific immune response. The oligosaccharides from buffalo colostrums were isolated by modified method of Kobata and Ginsburg, using chromatographic techniques, resulting in isolation of a novel pentasaccharide ‘Bubliose’. Stereoscopic structure of this oligosaccharide was supported by HSQC, TOCSY, COSY, HMBC experiments and mass spectrometry data confirming it to be a new pentasaccharide made up of Glc, Gal, GlcNHAc and GalNHAc linked together by β-(1→4) and β-(1→3) glycosidic linkages. The structure of ‘Bubliose’ was: <b>β-D Gal(1→4)-β-D Glc(1→3) β-D GlcNHAc(1→3)-β-D GalNHAc(1→4)-Glc Bubliose</b>