Qualitative And Quantitative Comparison Of Milk Oligosaccharides From Different Resources

Milk oligosaccharides are high abundance of oligosaccharides in the free form of milk. Milk oligosaccharides have the functions of anti-inflammation, increaseing immunity, promoting the development of brain and improving the cognitive ability. By qualitatively and relatived quantitatively analysising of different sources and different lactation period oligosaccharides, we can offer useful information for selecting reasonable and quality milk resources on the levels of glycomics. However, due to the complex structure of oligosaccharide and limiting analysis conditions, the study of oligosaccharide on these aspects were lack of in-depth research.In this study, we prepared the oligosaccharides from different sources of milk using ethanol precipitation. Removing impurities recur to C18 and carbon graphite solid phase extraction column. After labeling oligosaccharides with PMP, we used the disaccharide of GalAraPMP2 as the internal marker. The ESI-MS, MS/MS and HILIC-MS were selected to qualitatively and quantitatively analysis of different sources and different lactation period oligosaccharides. The results are described as follows:1. ESI-MS analysis showed, human milk has thirteen oligosaccharides compositions, while porcine, goat and bovine milk all have nine. Among which seven oligosaccharides compositions shared by four kinds of mammals:H2F, H2A, H3N, H3NF, H3NF2, H4N2, H4N2F.2. ESI-MS and HILIC-MS analysis showed, the human milk oligosaccharides H2F, H3NF2, H4N2F, H4N2F2, H4N2F3, H5N3F have two isomers and H3NAF has three isomers. The porcine milk oligosaccharides H2F and H2A have two isomers. The goat milk oligosaccharides H2F and H3NF2 have two isomers. We separate H2F2 from four kinds of mammal milk oligosaccharides and the composition of H3NA only from porcine milk oligosaccharides.3. With the passage of lactation, the diversity of structure and expression of human milk oligosaccharides increasing gradually while the porcine milk oligosaccharides are decreasing gradually. The proportion of fucosylated increase gradually and sialylated oligosaccharides decrease gradually exist both in human milk and porcine milk.4. The four kinds of mammals' mature milk contain twenty-five oligosaccharide chains. Sixteen oligosaccharides compositions exist:H2F; H2A; H2F2; H3N; H2NA; H3NF; H3NF2; H4N2; H3NAF; H4NF2; H4N2F; H3NA2; H4N2F2; H5N3; H4N2F3; H5N3F. Human milk has twenty-two oligosaccharides and the abundance (the ratio of samples oligosaccharide content with the internal standard) is 17.69. Porcine milk also has twenty-two oligosaccharides and the abundance is 2.66. Goat milk has eleven oligosaccharides and the abundance is 0.71. Bovine milk has five oligosaccharides and the abundance is 0.25. Human and goat both belong to high fucosylated and low sialylated oligosaccharides as well as contain higher proportion of H3N and H3NF.