Isolation and Structure Elucidation of Novel Yak Milk Oligosaccharide 'Nienose'

The properties of milk have been of scientific interest from various points of view like evolutionary, nutritionally and medicinally. It is sole nutrient source for newborn infants which is due to their structural diversity. The intestinal micro-biota protects against pathogens during early growth and development. The oligosaccharides isolated from various source of milk play a cardinal role in numerous physiological, pathological and biological activities. This study was aimed to find out the biologically active novel yak milk oligosaccharides. For this purpose 10 L of Yak milk was processed by modified method of Kobata and Ginsberg involving de-proteination, centrifugation and lyophilization followed by gel filtration HPLC and Column Chromatography which resulted into the isolation of a novel yak milk oligosaccharide namely nienose. The structure of Nienose was elucidated by chemical transformation, chemical degradation, H-1, C-13, 2D-NMR (COSY, TOCSY, HMBC and HSQC) and mass spectrometry. Glc-beta-(1 -> 3)Gal-beta-(1 -> 4)Glc GlcNac-beta-(1 -> 4)Glc-beta-(1 -> 3)GalNac-beta-(1 -> 2) Glc-alpha-(1 -> 3)GalNAc-beta-(1 -> 3)