烙印分子刚性对分子烙印手性固定手性拆分能力的影响

采用丙烯酰胺＋２－乙烯基吡啶复合功能单体烙印了刚性较小的苯甲氧羰基－Ｌ－丝氨酸、苯甲氧羰基－Ｌ－丙氨酸和具有一定刚性的苯甲氧羰基－Ｌ－脯氨酸，发现丙烯酰胺＋２－乙烯基吡啶体系对于分子刚性较小的分子也具有很好的烙印效果，表明不是烙印分子的刚性而是带有的与功能单体作用的化学功能基团才是实现分子烙印的关键。     

三元交联剂分子烙印手性固定相

采用２－乙烯基吡啶＋丙烯酰胺复合功能单体,以三甲氧基丙烷三甲基丙烯酸酯为三元交联剂制备了苯甲氧羰基－Ｌ－色氨酸烙印手性固定相,并与二元交联剂烙印相同氨基酸衍生物的情况进行了对比,发现三元交联剂在较小的用量下就可使分子烙印聚合物达到足够的交联度,实现烙印分子对映体的基线分离。     

单分散N-苯甲氧羰基-L-色氨酸表面分子印迹聚合物的手性拆分

采用多步溶胀与悬浮聚合联用的方法,以2-乙烯基吡啶(2-VP)为功能单体,二乙二醇二丙烯酸醋(DEGDA)为交联剂制备出N-苯甲氧羰基-L-色氨酸(N-Cbz-L-Trp)为模板的单分散分子印迹聚合物。高效液相色谱表征显示,制备的单分散分子印迹聚合物在很短的色谱柱中就能够实现对模板分子对映异构体的基线分离。以乙腈为流动相,进样量1000ng,流速0．25mL／min,柱温30℃时,该印迹聚合物对N-苯甲氧羰基-LD-色氨酸的分离度较好。     

复合碱性功能单体分子烙印手性固定相

采用丙烯酰胺+2-乙烯基吡啶的复合碱性功能单体体系制备了氨基酸衍生物分子烙印高效液相色谱手性固定相。在优化了功能单体与烙印分子的比例条件下对于烙印分子及其结构相似的对映体具有良好的手性分离能力。考察了烙印分子的化学基团对手性分离的影响,发现氢键作用力和较强的离子作用力在手性分离过程中均有贡献。     

功能单体对分子烙印手性固定相手性拆分能力的影响

系统考察了功能单体对非共价分子烙印手性固定相手性分离能力的影响,发现在非共价分子烙印手性固定相的制备中,功能单体与烙印分子之间存在着匹配性。丙烯酰胺可以与氨基酸衍生物的酰胺基团形成较强的氢键作用,碱性功能单体2-乙烯基吡啶则与其羧基形成较离子作用,两者的协同作用使复合功能单体丙烯酰胺+2-乙烯基吡啶对于氨基酸衍生物具有良好的烙印效果。竞争溶剂乙酸对样品与分子固定相间的非共价作用力有较大的影响,增加流动相中的竞争溶剂乙酸的含量,将减弱分子手性固定相与样品的酰胺键和羧基的氢键及离子作用,导致对样品的容量因子、手性选择性α及分离度f/g的减小。     

利用分子烙印手性固定相串联柱同时拆分两对对映体

采用复合功能单体制备了苯甲氧羰基－Ｌ－丝氨酸（Ｎ－Ｃｂｚ－Ｌ－Ｓｅｒ）和苯甲氧羰基－Ｌ－丙氨酸（Ｎ－Ｃｂｚ－Ｌ－Ａｌａ）烙印的分子烙印手性固定相。采用柱串联的方法,一次进样手性分离了苯甲氧羰基－ＤＬ－丝氨酸（Ｎ－Ｃｂｚ－ＤＬ－Ｓｅｒ）和苯甲氧羰基－ＤＬ－丙氨酸（Ｎ－Ｃｂｚ－ＤＬ－Ａｌａ）两对对映体,显示了分子烙印手性固定相在多对对映体同时手性分离的发展潜力。     

N-苯甲氧羰基-L-色氨酸为模板的单分散分子印迹聚合物微粒的制备

采用两步溶胀与悬浮聚合联用方法,以2-乙烯基吡啶(2-VP)为功能单体,二乙二醇二丙烯酸酯(DEGDA)为交联剂,成功制备出以N-苯甲氧羰基-L-色氨酸(N-Cbz-L-Trp)为模板的单分散分子印迹聚合物,并用扫描电镜、氮气吸附、拉曼光谱、高效液相色谱、热失重分析等测试手段进行表征.结果表明,分子印迹聚合物的平均粒径为6.3μm,多分散系数为1.03.拉曼光谱显示聚合物反应完全,模板分子洗脱充分.高效液相色谱表征显示,分子印迹聚合物在很短的色谱柱中即可实现对印迹分子对映异构体的基线分离.     

司它夫定分子烙印聚合物对模板分子的烙印效果研究

以抗爱滋病药物司它夫定为模板分子,甲基丙烯酸为功能单体,二甲基丙烯酸乙二醇酯为交联剂,用本体聚合法制备了分子烙印聚合物.本文考察了不同聚合条件和不同的单体与模板分子物料配比对产物分子烙印聚合物的吸附性能的影响.     

紫外光聚合法制备L-DBTA手性分子印迹聚合物的研究Ⅰ.紫外光聚合制备条件

以丙烯酸为功能单体,二苯甲酰-L-酒石酸(L-DBTA)为模板分子,三羟甲基丙烷三丙烯酸酯(TMPTA)为交联剂,采用光聚合方法合成了L-DBTA手性分子印迹聚合物,讨论了功能单体种类、功能单体用量、交联剂用量、引发剂用量、三乙胺用量、光聚合温度、光聚合时间、光强度等对L-DBTA手性分子印迹聚合物合成的影响。通过L-DBTA手性分子印迹聚合物对底物的结合实验分析,表明手性分子印迹聚合物对L-DBTA具有很好的识别性,L-DBTA的选择性比二苯甲酰-D-酒石酸(D-DBTA)高,其分离因子可达5．41。     

同时烙印分子烙印手性固定相

对采用两种对本同时烙印的方法,制备的氨基酸衍生物分子烙印手性固定相进行了考察。研究表明,如果两种烙印分子单独烙印的分子烙印手性对固定相对两种烙印分子具有较强的手性交叉拆分能力,那么这两种烙印分子同时烙印制得的分子烙印手性固定相就可对两种烙印分子均具有很好的手性分离能力,从而使专一性强的分子烙印手性固定相能同时分离多种对映体。     

Simultaneous Chiral Separation Using a Combinatorial Molecular Imprinting Phase

Molecular imprinting is a technology by which specific recognition sites can be producedby using a template molecule in the polymerization procedure. In recent years,molecular imprinting has become an important approach for the preparation of chiralstationary phase with predetermined selectivity'-'. So far, the commonly atilizedfunctional monomers include methacrylic acid', acrylamide' and 4-vinylpyridine',combined functional monomers such as methacrylic acid 2-vinylpyridine'-' andacrylamide…     

新型单分散血清白蛋白印迹微球的制备

以猪血清白蛋白（PSA）为模板,采用分级印迹方法,制备了新型单分散多孔蛋白质表面印迹微球．将PSA吸附在5gm粒径、1000A孔径的球形硅胶表面及孔内后,将甲基丙烯酰胺、甲基丙烯酸为功能单体、甲又双丙烯酰胺为交联剂的聚合物溶液,通过真空负压引入到硅胶孔内,并在室温下聚合24h．反应完成后,用3mol／L NH4HF2刻蚀硅胶,获得形状和结构与硅胶颗粒互补的PSA印迹聚合物微球．竞争吸附实验结果表明,在非模板蛋白质存在的情况下,实现印迹颗粒对模板蛋白的高选择性吸附,选择因子达到3．6,说明该印迹聚合物材料有望成为一种可以同生物抗体相媲美的新型亲和材料．     

表面分子印迹聚合物纳米线用于蛋白质的特异性识别

手性配体交换色谱是拆分手性化合物,特别是氨基酸和羟基酸对映体的一种有效方法,通常以光活性氨基酸或其衍生物为手性选择子,可通过键合及涂渍制备手性固定相,也可作为流动相添加剂来实现手性配体交换色谱分离分析,配体交换键合固定相需要完成载体和手性选择子之间的偶联,键合量因受到载体和制备条件的影响而较难控制,且柱效较低。     

Via protoporphyrin to the synthesis of levofloxacin‐imprinted polymer

A new molecularly imprinted polymer (MIP) for levofloxacin was prepared by the combined use of methacrylic acid and protoporphyrin as functional monomers. The adsorption properties of resultant imprinted polymers were evaluated by equilibrium rebinding experiments. The highest binding capacity of levofloxacin achieved from the optimized imprinted polymer in acetonitrile was 246.26 µmol/g with an imprinting factor of 2.05. A ?uorescence quenching effect was observed when a protoporphyrin‐based imprinted polymer was incubated in the solutions of levofloxacin. The results indicated that the protoporphyrin‐based MIPs were able to create higher binding cavities for template compared with MIPs using only methacrylic acid as a functional monomer. It should be expected that the cooperative use of the protoporphyrin with supplemental different functional monomers may be an alternative to obtain MIP with the improvement of the selectivity. Copyright © 2010 John Wiley & Sons, Ltd.     

Design of molecular imprinted polymers compatible with aqueous environment

The main problem of poor water compatibility of molecularly imprinted polymers (MIPs) was addressed in examples describing design of synthetic receptors with high affinity for drugs of abuse. An extensive potentiometric titration of 10 popular functional monomers and corresponding imprinted and Blank polymers was conducted in order to evaluate the subtleties of functional groups ionisation under aqueous conditions. It was found that polymers prepared using 2-trifluoromethacrylic acid (TFMAA) in combination with toluene as porogen possess superior properties which make them suitable for effective template recognition in water. The potential impact of phase separation during polymerisation on formation of high quality imprints has been discussed. Three drugs of abuse such as cocaine, deoxyephedrine and methadone were used as template models in polymer preparation for the practical validation of obtained results. The polymer testing showed that synthesized molecularly imprinted polymers have high affinity and selectivity for corresponding templates in aqueous environment, with imprinting factors of 2.6 for cocaine and 1.4 for methadone and deoxyephedrine. Corresponding Blank polymers were unable to differentiate between analytes, suggesting that imprinting phenomenon was responsible for the recognition properties.     

Synthesis and chromatographic evaluation of molecularly imprinted polymers prepared by the substructure approach for the class-selective recognition of glucuronides

Two series of molecularly imprinted polymers (MIPs) for the class-selective recognition of glucuronides have been prepared by using lipophilic substructures of the target analyte as template molecule and potent host monomers against oxyanions, that are expected to establish a strong stoichiometric interaction with the single carboxylic group of the template. The polymers were tested as stationary phases in liquid chromatography for specific recognition. A preliminary investigation of the imprinting properties of eleven MIPs was carried out, by comparing the retention time of the template and of structurally related compounds on the MIP column with that on the corresponding non-imprinted polymer (NIP). The two polymers showing the best performance were selected to further test cotinine, mycophenolic acid, testosterone and their respective glucuronides as model compounds. The high specificity obtained against glucuronides and the different chemical structure of the parent drug make the two MIPs class-selective imprinted receptors, also suitable for SPE application.     

The development of a semiautomated procedure for the synthesis and screening of a large group of molecularly imprinted polymers

A method for synthesis and evaluation of molecularly imprinted polymers (MIPs) on a semiautomated miniature scale is reported. This technique combines molecular imprinting with the combinatorial chemistry approach, allowing rapid screening and optimizations of libraries of MIPs. The polymers were prepared and evaluated in situ by rebinding utilizing powder dispensing and liquid handling systems. MIPs were prepared by a combinatorial approach using methacrylic acid (MAA), 4-vinylpyridine (4-VP), acrylamide, and styrene as functional monomers, and acetonitrile and toluene as porogenic solvents. A drug substance having aromatic, hydroxyl, -O-CONH2 functional groups was selected as the template molecule for this study. The MIP library results demonstrated that the polymer prepared with MAA as functional monomer shows the strongest binding affinity, and therefore, is preferred for the preparation of this particular template molecule. Due to the low consumption of reagents, and more importantly, the demonstrated ability of this method to effectively identify optimal imprinting conditions, this small-scale combinatorial protocol is well suited for fast and efficient screening and optimizations of MIPs.     

STUDY ON THE NON-COVALENT INTERACTION OF APIGENIN MOLECULARLY IMPRINTED POLYMERS BY SPECTROMETRY

The non-covalent interaction between aPigenin （API） and different functional monomers （α-methylacrylic acid （MAA）, acrylamide （AM）, 2-vinylpyridine （2-Vpy） and combined functional monomers （AM/2-Vpy）） was determined by UV spectrometry, and a series of apigenin molecularly imprinted polymers （API-MIPs） was synthesized with different functional monomers through molecular imprinting technology. The relationship between the non-covalent interaction of template/functional monomer and absorption of MIPs also was studied. The results showed that the order of the strength of the non-covalent interaction between API and different functional monomers in tetrahydrofuran （THF） is as follows： 2-Vpy〉 AM/2-Vpy〉AM〉MAA, which is positive correlation to the absorption capability of corresponding MIPs, and 2-Vpy is the optimum functional monomer among the used monomer for preparing API- MIPs.     

Molecular imprinting made easy

A simple method of molecular imprinting is presented that uses a single cross-linking monomer N,O-bismethacryloyl ethanolamine (NOBE) along with template, initiator, and solvent. This formulation eliminates the need for additional functional monomers and empirical optimization of relative ratios of functional monomers, cross-linkers, and template. In fact, utilization of NOBE alone often provides molecularly imprinted polymers (MIPs) with higher performance than MIPs incorporating functional monomer (e.g., methacrylic acid).