| Chromatographic column is the core of chromatography. Recently, monolithic capillary column emerged as an attractive separated tool because of its easy preparation and high performance. The boronate affinity chromatography (BAC) based on the boronic acid reagent is an important technology for recognization; enrichment and saparation of cis-diol containing biomolecules. It is no doubt that the combination of BAC and monolithic column and development their relevant research will improve the knowledge of cis-diol containing compounds. However, the development of boronate affinity is still imperfect, and it encounters some issues:1) because of the high pKa for the normal boronate reagent, it can not satisfy with the detection of biologic sample;2) the boronic acids are of broadspectrum affinity for the recognization of cis-diol compounds, and it can not specific capture different cis-diol compounds;3) the specific surface area of boronate affinity monolith is small, and the binding capacity for cis-diol is low;4) there are only seldom references mentioned the interaction between boronic acid and hydroxypropyl-amino biomolecules, but their interaction mechanism has not been reported. It is necessary to study the revelant mechanism in order to investigate the interferences in the boronate affinity and wide the function of boronate materials. To solve above issues, we carried out research from the following aspects:Firstly, we induced the electron-withdrawing group into the phenylboronic acod, and the monolithic capillary with the boronate affinity and hydrogeon separated mechanism was synthesized by in situ free radical polymerization. The4-(3-butenylsulfonyl) phenylboronic acid (BSPBA) is the functional monomer and N, N-methylenebisacrylamide (MBAA) is the crosslinker. Both MBAA and BSPBA are hydrophilic regeants, and the hydrophobility was reduced apparently. BSPBA was selected because its lower pKa value (7.0) enables stronger affinity at neutral pH. Besides, the strong electron-withdrawing sulfonyl group greatly reduces the hydrophobicity of the monomer and enhances the hydrogen bonding interaction. So, the monolithic capillary exhibited secondary separation capability, which enables2D separation on a single column.Secondly, we present a restricted access boronate affinity porous monolith, as a mimic of protein A with high selectity for the specific capture of antibodies. This biomimetic relies on a novel strategy that combines the steric hindrance of the porous monolith with the chemical selectivity of boronic acid. Meanwhile, original immunoaffinity and specificity of the captured antibodies were maintained. The boronic acid ligand well-located within appropriate nanochannels permits specific binding with the glycan of immunoglobulin G (IgG). The restricted access boronate affinity porous monolith can enrich and immobilize the andibodies under physiology pH conditioan, and it has the similar high selecitivity as protein A. Meanwhile, the antibodies captured by the monolith can maintain their original immunoaffinity and specificity to their defined antigens.Thirdly, in oder to improve the specific area surface of the boronate affinity, the melamine and TEPIC was selected as the copolymer regeant because of their high degree symetry in molecular stuecture. A monolith with high specific surface area homogeous3D skeleton and well hydrophilcility was preparaed. Compared with the references, the specific surface area was increased apparently. Furthermore, the monolith can specific capture the small biomolecular under physiology pH condition. At last, the method of NMR and HPLC was used to investigate the interaction between boroate and hyoxypropylamino compounds represented by β-blocker and β-agonist. The results shows that the hydroxypropylamino compounds can colvant through the interaction of B-N between boron atom and amino group, at the same, the hydrogen binding between the hydroxyl group in boronic acid and hydroxyl group in hydroxypropylamino compounds. This interaction similar as the convential boronate affinity, high background pH can enhance it and low background pH can weaken it, even destroy it. Moreover, the interaction between boroate and hyoxypropylamino compounds highly dependend on the protonated solvent environment. A large number of aprotic solvents will destroy the interaction, which afford a new measure for the regulating the interaction between boroate and hyoxypropylamino compounds. All the study provide important theoretical basis for the recognization, separation and enrichment of hyoxypropylamino compounds by phenylboronic acid materials. |
PDF Full Text Request