Structure elucidation of two novel yak milk oligosaccharides and their DFT studies

• Two isolated yak milk oligosaccharides, compound B (Grunniose) and compound F (Vakose), were novel and reported for the first time from any natural source or any milk and elucidated with the help of NMR spectroscopy and mass spectrometry.
• Using Gaussion 09 program at B3LYP method and 6-311G basis set, the geometries of compound B (Grunniose) and F (Vakose) have been optimized.
• The positive wave number values of optimized geometries show the stability of compounds. In optimized geometries compound B show lower in energy as compared to compound F.

Milk is a primary dynamic biological fluid responsible for development of neonates. Besides the other regular constituents it have oligosaccharides in it which are responsible for antitumor, anticancer, antigenic and immunostimulant activities. In our endeavor to find biologically active novel oligosaccharides, yak milk was taken, which is a rich source of oligosaccharide and its milk is used as antihypertensive, antioxidative and heart strengthening agent in folk medicine. For this purpose yak milk was processed by method of Kobata and Ginsburg followed by gel filtration HPLC and CC which resulted in the isolation of two novel milk oligosaccharides namely (I) Grunniose and (II) Vakose. The structure of purified milk oligosaccharides were elucidated with the help of chemical degradation, chemical transformation, spectroscopic techniques like NMR (1H, 13C and 2D-NMR), structure reporter group theory and mass spectrometry. The optimized geometry of compound Grunniose and Vakose, at B3LYP method and 6-311 + G basis set on Gaussian 09 program, show that the compound Grunniose is lower in energy as compared to compound Vakose.Compound Grunniose -Compound Vakose -Glc-β(1→3) Gal-β(1→3) GlcNAc-β(1→6) Gal-β(1→3) GlcNAc-β(1→3) Gal-β(1→4) Glc

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