Styrene-maleic Acid Polymer Derivatives Modified Silica Gel Chromatographic Materials:Preparation And Their Applications

Membrane lipids are characterized by structural and functional diversity.A comprehensive and accurate characterization of the structure of membrane lipids and a deeper understanding of the functions of membrane lipids depend on high-efficiency separation and analysis techniques.In recent years,in the field of cell membrane research,styrene-maleic acid copolymer(SMA)has attracted widespread attention.Due to its unique alternate structure and amphiphilic properties,SMA exhibits high solubilization ability for phospholipid molecules of various structures.Thus,SMA can be exploited as novel chromatographic stationary phase materials so as to improve the separation and analysis ability for complex membrane lipids.Herein,novel SMA derivatives based high performance liquid chromatographic(HPLC)stationary phase materials were prepared and their performances for phospholipid standards and phospholipid molecules extracted from gastric cancer cell were researched.Four chapters were contained in the thesis.The first chapter mainly introduces four aspects.In the first part,the structural and functional diversity,the challenges and main strategies for lipid analysis were introduced.Furthermore,the advantages of HPLC techniques as well as the necessity of developing new HPLC stationary phases were also illustrated.In the second part,the nanodiscs technology,especially the SMA-based nanodiscs,also known as styrene-maleic acid lipid particles(SMALPs)technology,was introduced.In the third part,the preparation of SMA and its derivatives was introduced.In the fourth part,SMALPs technique was extended.Finally,the research ideas of this paper were drawn out.In the second chapter,SiO₂-SMA-dodecanol column and SiO₂-SMA-amino acid column were prepared by thiol-ene click reaction and nucleophilic ring-opening reaction between anhydride and alcohol/amine.The SiO₂-SMA derivatives chromatographic stationary phase materials were characterized by Fourier transform infrared spectrometer and thermogravimetric analyzer,and the results can prove its successful preparation.The results of the retention mechanism investigation showed that both the SiO₂-SMA-dodecanol column and the SiO₂-SMA-amino acid column possessed the retention characteristics of a reversed-phase/hydrophilic mixed mode.Chromatographic separation performance research showed that the SiO₂-SMA-dodecanol column with stronger hydrophobic retention property can achieve good separation of alkylbenzenes,benzene derivatives and polycyclic aromatic hydrocarbons;SiO₂-SMA amino acid column with stronger hydrophilic retention property showed high-efficiency separation performance for amides and alkylbenzenes.The results of chromatographic separation performance comparison showed that the SiO₂-SMA-amino acid column had better separation selectivity for amides,phenols and thioureas,while the SiO₂-SMA-dodecanol column behaved better for the separation of anilines snd polycyclic aromatic hydrocarbons.In the third chapter,the SiO₂-SMA-dodecanol column and the SiO₂-SMA-amino acid column were further used for the separation of phospholipid standards.The SiO₂-SMA-amino acid column showed good separation selectivity for both the phospholipid classes and species,outperforming that of the SiO₂-SMA-dodecanol column.The SiO₂-SMA-amino acid column was further used for the separation of lipid extracts from gastric cancer cell membrane.Under normal phase and reversed-phase modes,phospholipid classes and phosphatidylcholine molecule species in gastric cancer cell membranes can be effectively separated and analyzed,revealing good potential in the separation and analysis of membrane lipids.In the fourth chapter,we summarized the full text and also introduced the future research scopes.