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1.
合成了可对氨基酸海因对映异构体选择性分离的分子印迹聚合物膜。利用紫外光谱法比较不同功能单体与模板分子的作用能力。以丙烯酰胺为功能单体,在极性溶剂中制备了5R-5氨-基酸海因的分子印迹聚合物膜,通过Scatchard分析法研究膜中结合位点情况。通过膜透过实验研究印迹膜对外消旋体的分离特性。Scatchard分析显示聚合物膜中形成了两类结合位点,其解离常数分别为1.88mmol/L和5.14mmol/L;选择性透过实验表明膜中形成了与5R-5氨-基酸海因分子形状和功能基因位置匹配的孔穴。与非印迹聚合物膜相比,印迹聚合物膜对对映体具有良好的选择性。 相似文献
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琥珀酸氯霉素分子印迹聚合膜的制备及其吸附特性研究 总被引:2,自引:0,他引:2
为制备对琥珀酸氯霉素分子具有特异性吸附的分子印迹聚合物膜, 利用模板分子琥珀酸氯霉素(HS-CAP)、功能单体甲基丙烯酸(MA)、交联剂乙二醇二甲基丙烯酸酯(EGDMA)、引发剂偶氮二异丁腈(AIBN)、溶剂四氢呋喃, 采用紫外光引发聚合的方法制备出含有HS-CAP分子印迹位点的印迹聚合微粒, 并使用相转化的方法, 制备含有这种HS-CAP分子印迹微粒的醋酸纤维素膜. 然后通过吸附实验检测该印迹膜的吸附特性, 与非印迹膜相比, 印迹膜对模板分子具有良好的特异性识别作用, 与印迹膜相互作用的模板分子溶液, 在作用前后浓度发生了显著的变化; 印迹膜对模板分子的识别作用主要集中于与模板分子相互作用的最初2 h之内, 并随作用时间的延长而降低; 当模板分子浓度介于0.2~0.0125 mg/mL这一范围内时, 模板分子溶液浓度越高, 印迹膜的吸附特性越明显. 本实验所制备的分子印迹聚合膜对模板分子具有特异性识别能力, 可以在下一步研制以分子印迹聚合膜为基础的检测氯霉素残留的传感设备中得到应用. 相似文献
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染料木素分子印迹聚合物的制备及其识别性能 总被引:1,自引:0,他引:1
以染料木素为模板分子、4-乙烯基吡啶(4-VP)为功能单体、乙二醇二甲基双丙烯酸酯(EGDMA)为交联剂、四氢呋喃(THF)为溶剂,采用本体聚合法制备了染料木素的分子印迹聚合物;采用静态平衡结合实验研究了该分子印迹聚合物对染料木素的结合能力和选择性能.结果表明,与化学组成相同的相应非印迹聚合物相比,染料木素分子印迹聚合物对染料木素的吸附性能和选择性更好.利用所合成的分子印迹聚合物作为固相萃取材料填充固相萃取小柱,可以选择性地从豆奶粉中分离、富集染料木素;此外,该分子印迹聚合物还有望用于其他豆制品的分析检验. 相似文献
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氟哌酸分子印迹共混膜的制备及结构表征 总被引:2,自引:0,他引:2
以氟哌酸为模板分子,α-甲基丙烯酸为功能单体,三甲氧基丙烷三甲基丙烯酸酯为交联剂,利用本体聚合方法制备了具有特异选择性的氟哌酸分子印迹聚合物,并利用聚砜与氟哌酸分子印迹聚合物共混的方法制备了分子印迹聚合物膜.运用红外光谱分析和透射电子显微镜研究了氟哌酸分子印迹聚合物的结构.运用扫描电子显微镜研究了分子识别膜的机理和吸附性能,运用平衡结合实验法证明了分子识别膜对氟哌酸表现出了较高的选择性. 相似文献
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蛋白质溶胶-凝胶包埋法分子印迹复合膜的制备及渗透机理研究 总被引:1,自引:0,他引:1
分别以牛血红蛋白、牛血清白蛋白和溶菌酶3种蛋白质为模板分子, 采用表面涂布的方法制备了在Nylon微孔滤膜表面覆盖有聚丙烯酰胺凝胶层的分子印迹复合膜, 并用扫描电镜对制备的分子印迹膜的表面形态和孔结构进行了表征, 发现支撑膜的表面及内部微孔表面均被一层丙烯酰胺凝胶所覆盖. 对用不同蛋白为模板制备的分子印迹膜进行了这3种蛋白的单一组分和双组分混合溶液渗透实验. 结果表明, 各蛋白底物在印迹膜上的渗透规律是特异性的识别位点和尺寸效应共同作用的结果. 特异性识别位点会选择性地识别模板分子, 从而使其渗透速度减慢; 尺寸效应主要体现在底物蛋白的体积越小其渗透越快. 相似文献
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本文以羧基化多壁碳纳米管为基材,结合芹菜素、丙烯酰胺、丙酮和乙二醇二甲基丙烯酸酯,在多壁碳纳米管表面合成对芹菜素具有特异性识别的分子印迹聚合物(MWCNTs-MIPs),并利用扫描电镜(SEM)、傅里叶变换红外(FT-IR)光谱和比表面积分析(BET)对该印迹聚合物进行表征。结果表明,在碳纳米管表面能均匀稳定地接枝一层厚度约为10~20nm的印迹材料。对聚合物的静态吸附性能和选择性进行研究,表明MWCNTs-MIPs的吸附效果优于其非印迹材料(MWCNTs-NIPs)。固相萃取实验表明该方法不仅重现性好,并能使芹菜素的纯度由0.53%增高至90.93%,回收率可达95.84%,富集因子高达171.6。可作为复杂天然产物中芹菜素分离提取材料。 相似文献
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作为传感器中最重要的研究方向之一,分子印迹传感器在近十年的发展中取得了巨大进展。分子印迹聚合物膜在转换器表面的固定化方法有涂膜法、原位引发聚合法和电化学聚合法等,其中电聚合法因具有制备简单快速、膜厚可控、膜与电极附着紧密、重现性好等优点而成为极具潜力的制备方法。该文评述了基于电化学聚合技术的分子印迹传感器的主要研究进展,对聚合膜制备过程中单体的选择和模板的去除进行了讨论,对电聚合制备的印迹传感器在传感领域的分析应用进行了总结,并在此基础上对其未来发展进行了展望。 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions. 相似文献