接枝型氨基酸分子印迹膜的制备及其手性拆分性能研究

发布时间：2018-03-03 16:09

本文选题：聚砜　切入点：氨基酸　出处：《中北大学》2017年硕士论文　论文类型：学位论文

【摘要】：氨基酸是构成有机体蛋白质的基本组成单元,且在食品、农药、药物合成及日用化工品等领域都有着十分重要的作用。氨基酸是一类手性化合物,其不同对映体物理化学性质完全相同,但却有着迥然不同的生理活性,故氨基酸对映体的手性分离备受关注,并得到了广泛的研究。膜拆分法是一种比较经济且易于规模化的分离方法,但一般的分离膜缺乏对映体分离的选择性。本课题结合了将分子印迹技术与膜技术,制备了新型的接枝型氨基酸单一对映体分子印迹膜,可有效地进行氨基酸外消旋体的拆分。通过分子设计的构思,以氯甲基化聚砜作为基膜,采用“接枝/交联聚合与分子印迹同步进行”的新型表面印迹技术,分别实施了L-天冬氨酸与L-谷氨酸在其表面的接枝交联聚合与分子印迹,制备了接枝型L-天冬氨酸分子印迹膜与L-谷氨酸分子印迹膜,考察了两种印迹膜对氨基酸对映体的识别选择性能和渗透分离性能。研究表明,两种接枝型印迹膜对两种氨基酸的对映体有着优良的识别选择性,能够成功地将氨基酸对映体拆分开。本研究设计与制备接枝型氨基酸单一对映体分子印迹膜的方法,具有明显的创新性,在生物与医药学等领域具有重要的科学价值与广泛的应用前景。首先,以氯甲基化聚砜(CMPSF)溶解在N,N-二甲基乙酰胺中,添加致孔剂聚乙二醇-400,采用浸没沉淀相转化法制得了CMPSF不对称多孔微滤膜,然后用乙二胺对其进行化学改性,制备了氨化改性膜AMPSF。以过硫酸铵为引发剂,使之与膜表面的氨基构成-NH_2/S_2O_8~(2-)表面引发体系,实施二甲基氨基甲基丙烯酸乙酯(DMAEMA)的在膜表面的接枝聚合,得到功能接枝膜PSF-g-PDMAEMA。考察了反应条件改变对反应的影响,得到了最佳条件。采用红外光谱(FT-IR)、光学显微镜(OM)及扫描电镜(SEM)对PSF-g-PDMAEMA进行了表征。采用紫外吸收光谱法考察研究了单体DMAEMA与天冬氨酸及谷氨酸的两种酸性氨基酸相互作用,也通过研究PSF-g-PDMAEMA对两种酸性氨基酸的吸附特性,进一步考察了单体DMAEMA与两种氨基酸分子之间的相互作用。研究结果表明,-NH_2/S_2O_8~(2-)表面引发体系中,DMAEMA在膜表面的接枝聚合能顺利进行,随着AMPSF表面氨基键合量的增大,接枝度也增大。最佳的反应温度为50℃,最佳的过硫酸盐浓度是单体质量的1.0 wt%,制得的接枝膜中PDMAEMA接枝度最高为0.64 mg/cm2。酸性氨基酸与DMAEMA间存在强静电相互作用和氢键作用,PSF-g-PDMAEMA对其可产生强烈的吸附效应,在p H=4时,吸附量最大,分别可达1.43mg/cm2、1.47 mg/cm2。紫外吸收光谱和等温吸附实验的结果的结果均表明,功能单体DMAEMA与两种氨基酸之间具有强烈的分子间作用,故本部分的研究结果为后续实施L-天冬氨酸和L-谷氨酸的分子印迹奠定了充分的理论基础。在上述实验基础上,分别以L-天冬氨酸(L-Asp)与L-谷氨酸(L-Glu)为模板对映体,采用N,N’-亚甲基双丙烯酰胺(MBA)作为交联剂,在表面引发体系-NH_2/S_2O_8~(2-)的作用下,分别实施了L-Asp和L-Glu在膜表面的分子印迹,然后将模板分子洗去,成功制得了接枝型L-天冬氨酸分子印迹膜L-Asp-MIM与L-谷氨酸分子印迹膜L-Glu-MIM。印迹膜的化学结构用FT-IR表征,表面形貌变化用OM进行观察,断面的孔结构变化由SEM观察。在对印迹膜充分表征的基础上,深入考察了反应条件对选择性系数的影响,确定了最佳印迹条件。最后采用静态法与动态渗透法研究了印迹膜对模板分子的结合与识别特性,探索了印迹膜对模板分子的渗透分离性能及其对氨基酸外消旋体的手性拆分性能。研究结果表明,L-Asp-MIM对L-Asp具有特异的识别选择性与优良的结合亲和性,相对于D-天冬氨酸,两种印迹膜对两种模板分子的选择性系数分别高达7.52和7.89,在“门效应”与“屏障效应”的共同作用下,印迹膜对模板分子具有优良的选择透过性,能够有效拆分氨基酸外消旋体溶液,且渗透液的光学纯度可达到82%左右。
[Abstract]:Amino acids are the basic unit of a protein in organism, and food, pesticide, pharmaceutical synthesis and daily chemical and other fields have a very important role. Amino acid is a kind of chiral compounds, the different enantiomers of physical and chemical properties are exactly the same, but there are totally different physiological activity, so the chiral amino acids the separation of concern, and has been extensively studied. Membrane separation method is an economical and easy scale separation method, but the general lack of separation membrane enantioselective separation. This paper combines molecular imprinting technology and membrane technology, new type of grafted amino acid enantiomers of molecular imprinting the film was prepared, which can effectively split the racemic amino acids. Through molecular design, with chloromethylated polysulfone as membrane, the grafting / crosslinking polymerization and molecular imprinting synchronization Novel surface imprinting technique ", were carried out and molecular imprinting polymerization of L- aspartic acid and glutamic acid in L- grafting and crosslinking the surface grafted L-, aspartic acid and glutamic acid molecularly imprinted membrane L- molecularly imprinted membrane was prepared, the effects of two kinds of amino acid imprinted membrane for enantiomeric recognition and selection of performance separation performance. The results show that two kinds of grafted imprinted membrane for two kinds of amino acid enantiomers with excellent selectivity, can successfully remove amino acid enantiomers separated. The system design and Study on Preparation of grafted amino acid enantiomers molecular imprinted membrane, which has obvious innovation that has important scientific value and application prospect in the fields of biology and medicine widely. First, with chloromethylated polysulfone (CMPSF) dissolved in N two, N- dimethyl acetamide, porogen polyethylene glycol -400 by immersion precipitation The phase inversion method with CMPSF asymmetric porous membrane, then its chemical modified with ethylenediamine, preparation of ammonia modified membrane AMPSF. with ammonium persulfate as initiator, and make the film surface amino -NH_2/S_2O_8~ (2-) surface initiator system, the implementation of two methyl amino ethyl methacrylate (DMAEMA) polymerization the film was obtained, PSF-g-PDMAEMA. grafted membrane function the effects of reaction conditions on the reaction effect, optimum conditions were obtained. By using infrared spectroscopy (FT-IR), optical microscope (OM) and scanning electron microscopy (SEM) of the PSF-g-PDMAEMA were investigated. The interaction was studied by ultraviolet DMAEMA monomer and aspartic acid the glutamic acid and absorption spectroscopy of two kinds of amino acids, but also through the study of PSF-g-PDMAEMA of two kinds of amino acid adsorption characteristics, further investigated between single DMAEMA and two kinds of amino acids The interaction. The results show that -NH_2/S_2O_8~ (2-) surface initiator and DMAEMA in membrane grafted polymerization can be carried out smoothly, with the increase of amino AMPSF bonded to the surface of the graft degree increases. The optimal reaction temperature is 50 DEG C, the best persulfate concentration is the monomer quality of 1 wt%. The grafting degree of PDMAEMA was the highest in presence of strong electrostatic interactions and hydrogen bonding interaction between DMAEMA and mg/cm2. 0.64 acidic amino acids in the grafted membranes prepared by PSF-g-PDMAEMA can produce strong adsorption effect on the P in H=4, the maximum adsorption amount, respectively. 1.43mg/cm2,1.47 mg/cm2. UV absorption spectra and isothermal adsorption experiment results show that that has a strong intermolecular interaction between functional monomer DMAEMA and two kinds of amino acids, so this part of the study results for the molecular imprinting foundation follow the implementation of L- aspartic acid and glutamic acid was fully L- The theoretical basis. On the basis of above experiments, using L- aspartic acid and glutamic acid (L-Asp) L- (L-Glu) as the template enantiomer, with N, N '- methylene bisacrylamide (MBA) as crosslinking agent, initiator system on the surface of -NH_2/S_2O_8~ (2-) under the effect of the implementation of the L-Asp, respectively. And L-Glu in molecular imprinting membrane surface, and then the template molecules wash, characterized by FT-IR chemical structure was prepared successfully grafted L- aspartic acid molecularly imprinted membrane L-Asp-MIM and L- glutamic acid molecularly imprinted membrane L-Glu-MIM. imprinted membrane, surface morphology changes were observed by OM, the pore structure change of cross-section observed by SEM based on. The characterization of the imprinted membrane on the full, in-depth study of the effects of reaction conditions on the selectivity coefficient, the optimum conditions are determined. Finally, imprinted by static method and dynamic method to study the permeability of the template molecule imprinted membrane binding and recognition characteristics, explore the India Chiral separation performance of membrane separation performance trace to template molecule and amino acid of racemic body. The results show that the L-Asp-MIM of L-Asp has specific recognition selectivity and excellent binding affinity to D- aspartic acid, the selectivity coefficients of two kinds of imprinted membrane for two template molecules were as high as 7.52 and 7.89. In the "common door effect" and "barrier effect", the imprinted membrane for the template molecule has excellent permeability, can effectively split racemic amino acid solution, and the penetration of the optical purity of liquid to about 82%.

【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.2;O647.3

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