齐多夫定替代模板分子印迹聚合物的制备及其在血清样品固相萃取中的应用

制备了齐多夫定(AZT)替代模板分子印迹聚合物(MIP)用于血清样品的前处理。利用计算机模拟选择最佳单体甲基丙烯酸和交联剂二乙烯基苯,用自制的替代模板(AZT酯化物)制备了AZT的MIP。将替代模板MIP作为固相萃取吸附剂,进行固相萃取并优化萃取条件。确定pH 7的KH2PO4缓冲溶液为上样溶剂,2%(V/V)乙腈/pH 7的KH2PO4缓冲溶液为淋洗剂,甲醇/乙酸(9:1,V/V)作为洗脱剂。渗漏实验结果显示齐多夫定MIP的吸附容量为9.10 mg/g,而非分子印迹聚合物(NIP)的吸附容量仅为1.77 mg/g。以AZT酯化物和拉米夫定为结构类似物,进行吸附实验,发现MIP具有高选择性。本文所制备的替代模板分子印迹聚合物在水溶液体系中表现出了很好的识别能力。血清样品经印迹聚合物固相萃取后,用高效液相色谱法测定,发现MIP萃取柱回收率为99.3%,NIP萃取柱仅为13.2%,说明替代模板MIP可用于血清样品中AZT的选择性分离富集,并可以避免模板渗漏。     

咖啡因分子印迹固相萃取柱的制备及应用

以咖啡因作为模板分子,α-甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,制备了咖啡因分子印迹聚合物(MIP)。与非印迹聚合物(NIP)相比,MIP对咖啡因具有更高的吸附容量和选择性,MIP和NIP对咖啡因的最大静态吸附量分别为28.1和16.5mg/g,相对选择因子为1.25。以咖啡因分子印迹聚合物为固相萃取填料,结合高效液相色谱(HPLC),建立了茶水中咖啡因浓度及人饮茶后血清中咖啡因浓度的检测方法。考察了洗脱剂种类和用量对咖啡因回收率的影响。当萃取柱依次以2mL水活化,水溶液上样,2mL水淋洗,6mL甲醇-乙酸(9∶1,V/V)洗脱,咖啡因在MIP固相萃取柱上的回收率达到97.5%,而在NIP柱上的回收率仅为54.9%。     

L-肉碱分子表面印迹聚合物的制备及其识别性能研究

以L-肉碱(L-carnitine)作为印迹模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,采用硅胶表面分子印迹技术合成了L-肉碱分子印迹聚合物(MIP)和非印迹聚合物(NMIP).通过紫外光谱研究了MAA与L-肉碱之间的结合作用.利用IR和SEM测试分别对产物进行了结构表征和表面形貌观察,说明分子印迹聚合物成功接枝到了硅胶表面.吸附动力学实验结果表明,MIP对L-肉碱有较好的识别性和吸附性;Scatchard分析表明该印迹聚合物中存在着一类等价的结合位点,最大表观结合量为71.00μmol/g,离解常数Kd=2.76×10-4mol/L;选择性吸附实验结果表明,MIP对L-肉碱的吸附结合量高于其D型异构体和其他类似物;拆分实验结果表明,MIP对DL-肉碱的拆分有一定作用.     

妥拉苏林分子印迹膜传感器的制备及识别特性研究

用电聚合的方法在金电极上制备了以妥拉苏林为模板分子的自组装邻氨基硫酚分子印迹膜传感器.通过差分脉冲伏安法研究传感器对妥拉苏林的响应特性,结果表明在优化的实验条件下,此传感器的峰电流响应值与妥拉苏林浓度在0.4～5μg·mL-1(r=0.9986)和5～120μg·mL-1(r=0.9953)范围内保持良好的线性关系,检测限为0.18μg·mL-1;相对标准偏差约为2.47%,响应时间约为3min.传感器具备较好的选择性和稳定性,初步用于人体尿液中妥拉苏林的分析,获得了较满意的结果.     

加替沙星印迹聚合物微球的合成及特异吸附性能

采用沉淀聚合法制备了加替沙星分子印迹聚合物(MIP)微球, 对其形貌和结构进行表征, 并对聚合反应条件进行优化|采用静态吸附试验研究聚合物对模板分子及其结构类似物的吸附行为和选择性识别特性. 结果表明, 在最佳实验条件下, 40 min印迹聚合物即可达到对底物的吸附平衡|在印迹聚合物中存在两类结合位点, 特异性和非特异性结合位点的最大吸附量分别为363和458 μmol/g|与化学组成相同的非印迹聚合物(NIP)相比, MIP对结构相似的喹诺酮类抗生素具有良好的选择吸附性能|该法制备的MIP微球易于再生, 放置3个月以后, 仍能够对喹诺酮类抗生素进行有效识别.     

克百威分子印迹聚合物的合成及其性能评价

以克百威为模板分子,甲基丙烯酸(MAA)为功能单体,二甲基丙烯酸乙二醇酯(EGDMA)为交联剂,采用沉淀聚合的方法制备了克百威分子印迹聚合物。通过红外光谱分析得到模板和功能单体的最佳配比为n(carbofuran)∶n(MAA)=1∶6。印迹聚合物的红外光谱测定结果表明,聚合物中存在与模板分子相互作用的特征基团;从印迹聚合物的扫描电镜图观察到分子印迹聚合物(MIP)与空白聚合物(NIP)的表面形态不同,可推论MIP存在与模板分子相互识别的结合位点。通过静态平衡结合法研究了模板分子聚合物的吸附能力、结合动力学和选择特性。结果表明,与非印迹聚合物相比,印迹聚合物对克百威具有较强的吸附特性和很好的专一选择性,3h后基本达到最大吸附量。采用固相萃取柱预处理样品,用高效液相色谱法测定自来水中10、50、100mg/L克百威的加标回收率为94%～117%,相对标准偏差(n=3)为2.5%～4.7%。     

分子印迹固相萃取联用高效液相色谱分离测定海水中的膝沟藻毒素GTX1,4

采用分子印迹技术,以鸟嘌呤核苷为虚拟模板,本体聚合,合成GTX1,4的分子印迹聚合物(MIP).傅里叶红外变换光谱(FT-IR)和扫描电子显微镜(SEM)的结果显示,MIP具有分布均匀、大小均一的孔穴.平衡吸附实验表明,分子印迹聚合物(MIP)比非分子印迹聚合物(NIP)具有更高的结合容量,对膝沟藻毒素GTXI,4有更好的选择性.用MIP填充固相萃取小柱(MISPE),以0.1 mol/L乙酸溶液为淋洗液,甲醇-水(95∶5,V/V)溶液为洗脱液时回收率最高,达到85.0％.用优化后的淋洗洗脱条件测定微小亚历山大藻和塔玛亚历山大藻藻液中的GTX1,4,分别为1.10和0.99 μg/L,RSD分别为3.3％和4.4％,说明本方法具有较好的检测限和较高的测定精密度.     

异戊巴比妥分子印迹聚合物的合成和识别性能研究

以异戊巴比妥为模板,分别以丙烯酰胺和甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,用本体聚合法制备了分子印迹聚合物(molecularly imprinted polymer,MIP)。考察了以不同功能单体合成的MIP对模板分子和结构类似物的识别能力和选择性。表明以丙烯酰胺为功能单体合成得到的MIP比甲基丙烯酸为单体的聚合物具有更好的再识别性和选择性,前者对异戊巴比妥的饱和吸附量可达到28．58μmol／g．为理论吸附量的40．9％。     

橄榄醇分子印迹聚合物的制备及评价(英文)

以橄榄醇为模板分子,α-甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,甲苯和十二醇为溶剂,通过本体聚合法制备了橄榄醇分子印迹聚合物。利用平衡结合实验、扫描电镜(SEM)及红外光谱(FTIR)对分子印迹聚合物(MIP)进行了表征,并用该聚合物进行了加标麦麸中橄榄醇的固相萃取(SPE)研究。平衡结合实验表明MIP对模板分子具有更好的识别性。Scatchard分析表明对橄榄醇分子的吸附存在2类不同结合位点,其中高亲和力结合位点和低亲和力结合位点的解离常数分别为0.021和1.002 mmol/L,相应的最大表观结合量分别为18.74和135.9 μmol/g。在优化的固相萃取条件下,MIP固相萃取柱对加标麦麸中橄榄醇的回收率达到97.8%~98.8%,相对标准偏差为2.8%~4.2%(n=5),线性范围为0.1~100 mg/L,检出限(S/N=3)为0.062 mg/L。与非印迹聚合物(NIP)柱及市售聚苯乙烯/二乙烯基苯(PLS)柱相比,MIP柱的选择性更强,回收率更高,纯化效果更好。     

柚皮苷印迹β-环糊精聚合物的制备及性能研究

以柚皮苷(NG)为印迹分子, β-环糊精为功能体, 六亚甲基二异氰酸酯为交联剂, 采用乳液聚合法制备了对NG具有特定识别能力的吸附材料: 棒状印迹聚合物. 扫描电镜及比表面分析仪测试结果表明印迹聚合物具有较大的孔隙及比表面积|红外及核磁共振谱研究证实了识别位点来自β-环糊精与NG羟基间的氢键作用. 采用平衡吸附实验方法研究了聚合物的吸附性能和选择性能. 实验结果表明, 棒状印迹聚合物(RMIP)对NG具有较高的亲和性和选择性. Scatchard分析表明, MIP在识别NG过程中存在2类结合位点: K_D1＝0.016 mmol/L, B_max1＝15.31 μmol/g, K_D2＝0.24 mmol/L, B_max2＝98.41 μmol/g. 当NG浓度为 0.02 mg/mL时, MIP及相应NIP对 NG的分配系数 K_{D 分别为4.38和2.86, 印迹因子α为1.53.}     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

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.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

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.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

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.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

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.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

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.