Chemical characterization of the oligosaccharides in Bactrian camel (Camelus bactrianus) milk and colostrum

Abstract

Bactrian camel milk and colostrum are commonly used as foods in Mongolia, whose people believe that these products promote human health. It has been hypothesized that milk oligosaccharides are biologically significant components of human milk, acting as receptor analogs that inhibit the attachment of pathogenic microorganisms to the colonic mucosa, and as prebiotics, which stimulate the growth of bifidobacteria within the infant colon. To evaluate their biological significance, we studied the oligosaccharides present in samples of Bactrian camel milk and colostrum. Using (1)H-nuclear magnetic resonance spectroscopy, we identified and characterized the following oligosaccharides of camel colostrum: Gal(β1-4)[Fuc(α1-3)]Glc (3-fucosyllactose), Gal(β1-3)Gal(β1-4)Glc (3'-galactosyllactose), Gal(β1-6)Gal(β1-4)Glc (6'-galactosyllactose), Neu5Ac(α2-3)Gal(β1-4)Glc (3'-sialyllactose), Neu5Ac(α2-6)Gal(β1-4)Glc (6'-sialyllactose), Neu5Ac(α2-3)Gal(β1-3)Gal(β1-4)Glc (sialyl-3'-galactosyllactose), Neu5Ac(α2-6)Gal(β1-4)GlcNAc(β1-3)Gal(β1-4)Glc (sialyllacto-N-tetraose c), Neu5Ac(α2-3)Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (sialyllacto-N-novopentaose a), Gal(β1-3)[Neu5Ac(α2-6)Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (sialyllacto-N-novopentaose b); and Neu5Ac(α2-6)Gal(β1-4)GlcNAc(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (monosialyllacto-N-neohexaose). The oligosaccharides in the mature camel milk were characterized as 3'-galactosyllactose, Gal(β1-3)[Gal(β1-4)GlcNAc(β1-6)]Gal(β1-4)Glc (lacto-N-novopentaose I), and 3'-sialyllactose.