Preparation And Structural Characterization Of Gangliosides

Objective A fast and stable off-line multi-dimensional chromatography separation and purification method was developed for the preparation of gangliosides.At the same time,the mass spectrometry analysis rules were summarized for structure characterization,which laid the foundation for the research of gangliosides.Methods In order to obtain the ganglioside compounds,an X5 H chromatography column developed by our laboratory was used as the first dimension chromatography to elute ganglioside fractionations linked by different sialic acid numbers,such as GA(asialoganglioside),GM(monosialoganglioside),GD(disialoganglioside),GT(trisialoganglioside)and GQ(quadrisialogangliosides).The obtained one-dimensional fractions was further two-dimensionally purified using a self-made C8 HC reversed-phase chromatography,and finally a series of ganglioside compounds were obtained.In the aspect of ganglioside structural characterization,ganglioside standards were used to summarize the mass spectrometry fragmentation rules firstly,and then the fragmentation rules were used to characterize the compounds we separated by two-dimension chromatography.In addition,the core structures of GM1 saccharide chains were deeply analyzed using liquid chromatography coupled with mass spectrometry.Results Twenty-eight gangliosides were purified by the designed off-line two-dimensional chromatography.The mass spectrometry fragmentation rules was summarized,and the structure of the prepared gangliosides was characterized.The ratio of different core structures of GM1 saccharide chains were deeply analyzed,and it was found that two major core structures(Ganglio and Neolacto)existing in the GM1 saccharides chain with the ratio of 98.2 : 1.8.Conclusion A systematic two-dimensional chromatography was develop to separate gangliosides from total extract,and 28 compounds are purified.The definite structures of separated gangliosides were further identified by mass spectrometry.The experimental resultsin this thesis provide a novel method for purification and structural characterization of gangliosides,which is of great significance for the research of gangliosides.