Molecular imprinting on amphiphilic folded polymers for selective molecular recognition in water

We report amphiphilic folded polymers with imprinted nanocavities for selective molecular recognition in water. For this, a molecular imprinting technique is applied to the polymer synthesis: amphiphilic polymer micelles interacting with template molecules are crosslinked in water to fix the folded architecture and memorize the template structure within the polymers; the removal of the templates provides imprint polymers bearing template-specific nanospaces. Here, a hydrophilic dye bearing two anionic groups, Orange G (OG), is used as a model template. For the imprinting, we design amphiphilic random copolymers bearing hydrophilic poly(ethylene glycol) (PEG) chains, hydrophobic olefin groups, and quaternary ammonium groups that can interact with the template. The copolymers were prepared by living radical polymerization and post functionalization. In the presence of OG and methyl blue (MB), the imprinted nanocavity polymers simultaneously capture both of the dyes in water. The total number of encapsulated dyes increased with increasing the number of polymer-bound quaternary ammonium groups. The selectivity of OG against MB increased with the crosslinking density, while imprint polymers encapsulated OG more efficiently than nonimprint polymers. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 215–224     

Syntheses of fluoroalkyl derivatives of two biologically active oligopeptides

Fluoroalkyl derivatives of two biologically active oligopeptides [ enkephalin,[(m-C2F4Cl)Tyr1]-Leu-enkephalin and [(m-COCF2Cl)Tyr2]-melanocyte-stimulating hormone releasing hormone have been synthesized.Studies on the activities of these peptides are underway.     

Installation of a ratchet tooth and pawl to restrict rotation in a cyclodextrin rotaxane

Eight new [2]rotaxanes have been prepared, incorporating an alpha-cyclodextrin as the rotor, a stilbene as the axle, and trinitrophenyl substituents as capping groups. Strategies have been devised to elaborate these by linking the rotor to the axle, to produce two new [1]rotaxanes. Rotational motion in a selection of these rotaxanes has been investigated through the application of two-dimensional NMR spectroscopy by performing TOCSY, DQF-COSY, ROESY and HMQC experiments. This has shown that a methoxyl group incorporated on the stilbene and a succinamide joining the stilbene and the cyclodextrin behave analogously to a ratchet tooth and pawl, respectively, to restrict rotation.     

绿色分子印迹技术简论

解析了绿色分子印迹技术(GMIT)的概念;结合水相和其他新型分子印迹技术、聚合物辅助设计及新型原材料的发展,简要阐述GMIT的发展动向.指出在绿色化学日益深入人心的今天,有必要深入探索和发展绿色分子印迹技术,从而拓展分子印迹技术研究领域、促进绿色化学的发展.     

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．     

分子印迹技术在蛋白质识别中的应用进展

分子印迹技术是一种制备具有分子识别能力的聚合物的有效技术,已经广泛应用于制备对小分子具有选择性的分子印迹聚合物,但制备能够特异性识别生物大分子--蛋白质的分子印迹聚合物的研究仍然具有挑战性。本文讨论了制备蛋白质分子印迹聚合物的难点,评述了目前印迹蛋白质的方法及各自的优缺点,展望了蛋白质印迹技术的发展趋势。     

蛋白质分子印迹技术载体形式的研究进展

现代生物技术产品分离成本很高,分子印迹技术以其优良的操作稳定性为蛋白质分离提纯提供了一种新的方法,合成蛋白质分子印迹聚合物具有巨大的应用价值,又极具挑战性,已成为各国科学工作者们研究的热点。本文对蛋白质分子印迹过程中使用的载体形式进行了综述,对不同形式载体的使用特点进行了总结,详细叙述了常见的载体形式如硅胶、合成树脂球、高分子膜、云母、凝胶以及一些新型的载体类似形式如环糊精和壳聚糖等,并探讨了目前蛋白质分子印迹技术存在的问题及其应用前景。     

分子印迹技术研究进展

分子印迹技术是制备对特定目标分子具有特异性识别能力的高分子材料的技术,所制备的高分子材料被称为分子印迹聚合物.分子印迹聚合物因具有预定性、识别性和实用性三大优点已广泛应用于分离、模拟抗体与受体、催化剂以及仿生传感器等方面和领域,显示出了广泛的应用前景.作者对分子印迹技术的发展历史、基本原理、分类、应用现状以及一些新的研究热点进行了综述.     

分子印迹技术在天然产物有效成分分离纯化中的应用

天然产物体系复杂,大分子和小分子、生命和非生命物质共存,多存在结构相近的异构体,且有效成分含量低,采用一般的分离方法富集难度较大。分子印迹技术是制备高选择性分离介质的有效技术手段,分子印迹聚合物(MIP)的选择性强,分离操作简单,在各种分离纯化中展现了良好的应用前景。本文对近年来分子印迹技术在天然产物活性组分(如生物碱、甾体、多元酚、黄酮等)的分离纯化中的应用进行了综述,并介绍了本课题组利用MIP从天然产物中分离纯化莽草酸等活性成分的研究进展。     

Molecular imprinting of peptides and proteins in aqueous media

Molecular imprinting has received significant attention in recent years, as it provides a viable method for creating synthetic receptors capable of selectively recognizing specific target molecules. Despite significant growth within the field, the majority of template molecules studied thus far have been characterized by their low molecular weight and insolubility in aqueous systems. In biological systems, molecular recognition events occur in aqueous media. Therefore, in order to create molecularly imprinted polymers capable of mimicking biological processes, it is necessary to synthesize artificial receptors which can selectively recognize their respective target biological macromolecules such as peptides and proteins in aqueous media. In this review, we discuss the challenges associated with the imprinting of peptides and proteins in aqueous media. In addition, we discuss the significant progress which has been made within the field.     

Molecular imprinting using monomers with solid-state polymerization

Molecular imprinting of two diolefinic compounds with solid-state photopolymerization, 2,5-distyrylpyrazine (DSP) and diethyl p-phenylenediacrylate (EPA), was demonstrated. Solid nanoscale particles of the monomer were produced and deposited onto the surface of a surface acoustic wave (SAW) transducer using the technique known as rapid expansion of supercritical solutions (RESS). The particles were polymerized by UV light in the presence of an alkane template vapor. Both imprinted and non-imprinted devices were tested upon exposure to a variety of alkane vapors in the gas phase. The results demonstrate an enhanced sensitivity to vapors at or below the size of the template. A size exclusion mechanism of recognition is proposed.     

计算机分子模拟在分子印迹技术中的应用

传统的分子印迹技术对模板分子、功能单体、交联剂、致孔剂等的筛选往往依靠经验,常通过反复实验对合成条件进行优化,存在实验周期长、耗材量大等问题。计算机分子模拟技术的应用在实验过程中起到可预见性指导作用,可以实现精准识别位点的裁制、识别驱动力的设计,通过结合能等物化特征参数计算优化识别体系的稳定性,从而合理选择模板分子、功能单体、交联剂、致孔剂,优化聚合条件,以提高聚合物识别特异性和亲和力,缩短实验周期,更符合绿色化学的理念。本文简单介绍了计算机分子模拟技术,重点对其在分子印迹技术中的指导作用进行了综述,并对其在分子印迹技术中的应用进行了展望。     

Combination of capillary electrophoresis and molecular modeling to study the enantiomer affinity pattern between β‐blockers and anionic cyclodextrin derivatives in a methanolic and water background electrolyte

In order to have deep insights into the mechanisms of enantiomer affinity pattern in both aqueous and non‐aqueous systems, an approach combining capillary electrophoresis and molecular modeling was undertaken. A chiral β‐blocker; acebutolol, was enantioseparated in aqueous capillary electrophoresis and non‐aqueous capillary electrophoresis using two anionic β‐cyclodextrin derivatives. The enantiomer affinity pattern of acebutolol was found to be opposite when an aqueous background electrolyte was replaced with non‐aqueous background electrolyte in the presence of heptakis(2,3‐di‐O‐acetyl‐6‐sulfo)‐β‐cyclodextrin but remained the same in the presence of heptakis(2,3‐di‐O‐methyl‐6‐sulfo)‐β‐cyclodextrin. Molecular docking of acebutolol into two β‐cyclodextrin derivatives indicated two distinct binding modes called ‘up’ and ‘down’ conformations. After structure optimization by molecular dynamics and energy minimization, both enantiomers of acebutolol were preferred to the ‘up’ conformation with heptakis(2,3‐di‐O‐methyl‐6‐sulfo)‐β‐cyclodextrin while ‘down’ conformation with heptakis(2,3‐di‐O‐acetyl‐6‐sulfo)‐β‐cyclodextrin. The further calculation of the complex energy with solvent effect indicated that heptakis(2,3‐di‐O‐acetyl‐6‐sulfo)‐β‐cyclodextrin had higher affinity to S‐acebutolol than R‐acebutolol in non‐aqueous capillary electrophoresis while it showed better binding to R‐acebutolol in aqueous capillary electrophoresis. However, the heptakis(2,3‐di‐O‐methyl‐6‐sulfo)‐β‐cyclodextrin bound better to R‐acebutolol in both aqueous and non‐aqueous capillary electrophoresis, implying that the binding mode played more important role in chiral separation of heptakis(2,3‐di‐O‐methyl‐6‐sulfo)‐β‐cyclodextrin while the solvent effect had prevailing impact on heptakis(2,3‐di‐O‐acetyl‐6‐sulfo)‐β‐cyclodextrin.     

分子印迹技术在生物大分子分离识别中的应用

分子印迹技术是近些年发展起来的模拟抗体-抗原相互作用原理的新技术。该文介绍了分子印迹技术的产生和发展,重点介绍了生物大分子印迹聚合物的制备条件、聚合方法及其识别机理,并对该技术的应用前景及目前存在的问题进行了探讨。     

分子印迹技术在蛋白质分离分析中的研究进展

蛋白质结构复杂,种类多样,与各种生命活动密切相关。大部分蛋白质在生物体中含量极低,对其分析检测带来极大困难。因此实现复杂生物样品中蛋白质的选择性识别与分离,对实现蛋白质的分离分析意义重大。通过分子印迹技术制备的分子印迹聚合物含有与模板分子大小、形状一致,官能团相互匹配的三维印迹空穴,在蛋白质的选择性识别与分离领域显示出了巨大的发展潜力。但是,由于蛋白质具有尺寸较大、构型易变、结构复杂等特点,分子印迹技术在蛋白质印迹中面临着巨大挑战。该文在介绍几种新型分子印迹技术包括表面印迹、抗原决定基印迹和金属螯合物印迹的基础上,综述了近3年分子印迹技术在蛋白质分离分析方面的应用,并对其发展进行了总结与展望。     

Molecular Imprinting of Cyclodextrins Leading to Synthetic Antibodies

Molecularly imprinted cyclodextrins were applied to HPLC stationary phases forefficient recognition of nano-scaled guests in water. When cholesterol was usedas a template molecule, the imprinted polymer selectively retained this guest morestrongly and selectively than did non-imprinted polymer. The imprinting effect inthe retention behavior was consistent with previously reportedphysicochemical analyses.Immobilization of the imprinted cyclodextrin polymer on the surfaceof silica gel in water was also successful. The polymer-silica gel compositesobtained had sufficient physical strength, and were useful for HPLC stationary phases. Thesemolecularly imprinted polymers could recognize steroids, amino acid derivatives,dipeptides, and antibiotics. Moreover, we found that the enantio-selectivity towardthe template molecules was significantly promoted. This methodology has greatpotential for the recognition of large guest molecules in water, and can be analternative to affinity chromatography for the separation of bio-molecules.     

Molecular imprinting in ultrathin titania gel films via surface sol-gel process

Recent progresses of molecular imprinting in metal oxide matrices were summarized. Application of the surface sol-gel process to mixtures of organic carboxylic acids and titanium alkoxide provides ultrathin layers of titania gel (10-20 nm thick), in which molecule-sized cavities are kept intact upon removal of the organic templates. The imprinted cavity reflects the structural and functional features of the template molecule, and the enantioselective imprinting of dipeptide isomers is observed. Robustness and flexibility of the ultrathin titania layer is demonstrated by the formation of interconnected titania hollow structures. Possible practical applications and unsolved problems of this technique are discussed.     

Molecular imprinting: a dynamic technique for diverse applications in analytical chemistry

Continuous advances in analyzing complex matrices, improving reliability and simplicity, and performing multiple simultaneous assays with extreme sensitivity are increasing. Several techniques have been developed for the quantitative assays of analytes at low concentrations (e.g., high-pressure liquid chromatography, gas chromatography, immunoassay and the polymerase chain reaction technique). To achieve highly specific and sensitive analysis, high affinity, stable, and specific recognition agents are needed. Although biological recognition agents are very specific and sensitive they are labile and/or have a low density of binding sites. During the past decade molecular imprinting has emerged as an attractive and highly accepted tool for the development of artificial recognition agents. Molecular imprinting is achieved by the interaction, either noncovalent or covalent, between complementary groups in a template molecule and functional monomer units through polymerization or polycondensation. These molecularly imprinted polymers have been widely employed for diverse applications (e.g., in chromatographic separation, drug screening, chemosensors, catalysis, immunoassays etc.) owing to their specificity towards the target molecules and high stability against physicochemical perturbations. In this review the advantages, applications, and recent developments in molecular imprinting technology are highlighted.