喷射式电化学发光猝灭法快速测定莱克多巴胺

基于莱克多巴胺对Ru(bpy)2+3/N-丁基二乙醇胺电化学发光体系的强烈猝灭效应,结合喷射式分析技术,建立了一种能够快速、灵敏地用于检测莱克多巴胺残留的新方法。在优化后的实验条件下,体系的相对发光强度与莱克多巴胺的浓度在1.0×10-9~1.0×10-5 g/mL范围内呈良好的线性关系,检测限(S/N=3)为5.0×10-10 g/mL。对含1.0×10-8 g/mL莱克多巴胺的发光体系进行11次重复测定,所得相对标准偏差为1.23%。该方法可用于猪尿中莱克多巴胺残留的测定。     

Keggin 型磷钨酸盐修饰碳糊电极传感多巴胺的研究

多金属氧酸盐作为一类阴离子簇合物,由于其结构的多样性和尺寸大小的可调变性,在电化学、催化和药学等领域引起了人们的广泛关注.本文制备了多酸Co(C₁₅N₆H₁₂)₂[PW₁₂O₃₈]·5H₂O（Co[PW₁₂O₃₈]）修饰碳糊电极并通过电化学阻抗谱、循环伏安法以及差分脉冲伏安法对多巴胺的传感性能进行了研究.对其制备条件和检测条件分别进行了优化.在优化条件下,制备的传感器对多巴胺具有良好的选择性和灵敏度的检测能力.多巴胺的线性响应范围为8.0x10^-6 mol·L^-1至3x10^-5 mol·L^-1,灵敏度为0.039 μA·(μmol·L^-1)^-1,检出限（S/N=3）为5.4 x10^-6 mol·L^-1. 制备的多酸修饰碳糊电极用于检测多巴胺表现出良好的稳定性和重现性,并且对抗坏血酸、尿酸等常见的干扰物质,具有良好的抗干扰性. 多酸修饰的碳糊电极制备过程简单方便,成本低,传感性能良好,对应用于电化学传感器检测多巴胺具备潜在的应用前景.      

莱克多巴胺、沙丁胺醇与克伦特罗三合一免疫亲和柱的制备及应用

将莱克多巴胺抗体和克伦特罗抗体偶联到溴化氰活化的琼脂糖凝胶上,制成免疫亲和柱,对其柱性能进行测试,并优化了使用条件,结合高效液相色谱-串联质谱对实际饲料样品进行检测。结果表明:该免疫亲和柱对莱克多巴胺、沙丁胺醇、克伦特罗的柱容量依次为49,27,24 ng/mL胶,保质期为5个月,最佳洗脱液为甲醇,对3种物质的回收率为78.9%~96.5%,RSD均小于1.5%,检出限为0.1~1 ng/g。该法可同时检测饲料中3种瘦肉精的含量。     

莱克多巴胺免疫亲和柱的制备与应用研究

用多元酸酐与混合酸酐相结合的方法合成了莱克多巴胺(Rac)抗原,免疫动物获得特异性抗体,并以蛋白A柱纯化得到IgG抗体。琼脂糖凝胶(Sepharose 4B)经溴化氰(CNBr)活化后与IgG抗体偶联,制备莱克多巴胺免疫吸附剂。据此建立了尿液中莱克多巴胺的免疫亲和柱净化/液相色谱-荧光法(HPLC-FL)测定的分析方法。免疫制备特异抗体50%抑制浓度(IC50)为5μg/L。Sepharose 4B经CNBr活化后与2 mg抗体的偶联率达87.4%。1 mL吸附剂的柱容量为67.57 ng。尿液中莱克多巴胺的回收率为76%~90%。     

应用表面增强拉曼光谱技术快速检测尿样中的β-兴奋剂

应用表面增强拉曼光谱技术与化学计量法相结合分析克伦特罗、沙丁胺醇和莱克多巴胺3种β-兴奋剂的标准溶液.在取自10头猪的尿样中,分别添加5个不同浓度的莱克多巴胺(1～20 mg/L),采用快速的液液萃取法对样品进行前处理,再进行表面增强拉曼测试.结果表明,克伦特罗和沙丁胺醇标准溶液的最低检测浓度为2 μg/L,莱克多巴胺标准溶液的最低检测浓度为0.1 mg/L;通过偏最小二乘法建立模型进行定量分析,3种药物的实际值与预测值的相关系数(R2)为0.9134～0.9368;本方法可检测尿样中1 mg/L莱克多巴胺,经外部验证后模型的实际值与预测值的相关系数(R2)为0 881,相对分析误差(RPD)为2.83;分析尿液中的莱克多巴胺含量所需时间小于30 min,为快速检测莱克多巴胺提供新途径.     

铜离子掺杂双金属纳米球免疫传感器检测前列腺特异性抗原

以比表面积大、结合位点多的金铂纳米球杂化二氧化锡石墨烯(GS-SnO₂@Au-Pt)修饰玻碳电极,作为传感平台固定捕获抗体(Ab₁),铜离子掺杂金银纳米球(Au-Ag@Cu²⁺)与检测抗体(Ab₂)结合作为免疫探针,构建夹心型电化学免疫传感器,并用于检测前列腺特异性抗原(PSA)。基于Cu²⁺和Cu⁺之间的电子转移,以及金银双金属协同效应增强检测信号,通过方波伏安法(SWV)检测,在0.25 V处获得尖锐信号峰。结果表明,该免疫传感器具有较宽的线性范围(1 fg/mL～10 ng/mL)和较低的检出限(0.34 fg/mL),在PSA临床检测中有潜在应用前景。     

基于Pd/COF-LZU1非标记型C-反应蛋白免疫传感器的研制

采用溶剂热法, 通过有机单体合成了一种亚胺键连接的共价有机框架材料(COF-LZU1); 在常温常压条件下, 通过后合成的方法将贵金属钯(Ⅱ)引入到COF材料中, 合成了复合材料Pd/COF-LZU1, 该材料具有优良的催化性能. 利用Pd/COF-LZU1多孔复合材料将C-反应蛋白(CRP)抗体(anti-CRP)固定在玻碳电极表面, 构建了一种非标记型CRP免疫传感器. 当抗体与抗原发生免疫反应时, 形成的免疫复合物会阻碍电化学探针[Fe(CN)₆]^4-/3-的电子传递, 降低其响应电流, 从而实现CRP的快速检测. 采用交流阻抗和差示脉冲伏安法(DPV)考察了免疫传感器的电化学特性, 同时考察了测试底液的pH值、 抗原培育时间和抗体固定浓度等实验条件对传感器性能的影响. 在最优的实验条件下, 采用DPV法对CRP进行检测的线性范围为5~180 ng/mL, 检出限为1.66 ng/mL, 线性相关系数为0.992.     

MAP-H2O2-HRP伏安酶联免疫分析测定南方菜豆花叶病毒

提出间氨基酚(MAP)-H₂O₂-辣根过氧化物酶(HRP)伏安酶联免疫分析新体系,并用于南方菜豆花叶病毒(SBMV)的测定.以线性扫描二阶导数伏安法检测HRP催化H₂O₂氧化MAP的产物,用于游离HRP及SBMV的测定,灵敏度均高于经典的ELISA显色光度法.本法对HRP测定的线性范围为1.0×10^-8～1.0×10^-6g/L,检测限为3.8×10^-9g/L;对SBMV测定的线性范围为4.0～5000ng/mL,检测限为4.0ng/mL.用所建立的方法测定病毒感染病叶澄清液的最高稀释比为1∶1.5×10⁵,并与现行的ELISA显色光度法进行对照,二者相关性很好.     

基于金属-有机骨架Fe-MIL-88NH2的凝血酶适体传感器

合成了一种含氨基的金属-有机骨架材料Fe-MIL-88NH₂, 并研制一种基于Fe-MIL-88NH₂的适用于快速检测凝血酶的三明治型适体传感器. 以掺杂金纳米颗粒的共价有机框架材料Au NPs@COF-LZU-8复合材料作为固定基质固定凝血酶适体Ⅰ, 凝血酶与适体Ⅰ特异性结合后, 再与通过戊二醛交联制得的凝血酶适体Ⅱ(Apt)-Fe-MIL-88NH₂复合物结合, 采用差分脉冲伏安法直接检测标记物Fe-MIL-88NH₂中铁离子(Fe³⁺)的还原峰电流. Fe-MIL-88NH₂中Fe³⁺的电流响应值与凝血酶浓度在0.5~200 ng/mL范围内呈正比, 线性相关系数为0.987, 检测限为0.167 ng/mL. 该传感器简化了实验步骤, 扩大了MOFs的应用范围, 为设计生物传感器开辟了新思路.     

基于分层Ti3C2 MXene纳米片的多巴胺电化学检测

选择多巴胺作为标志物，构建了基于分层Ti₃C₂ MXene(DL-Ti₃C₂)纳米片的电化学检测平台。通过原位锂离子插层法成功合成了DL-Ti₃C₂纳米片。采用扫描电镜和X-射线粉末衍射等手段对Ti₃C₂ MXene纳米片进行了微观形貌及结构表征。利用循环伏安法研究了多巴胺的电化学行为，结果表明DL-Ti₃C₂纳米片比多层Ti₃C₂ Mxene(ML-Ti₃C₂)纳米片具有更优异的电化学分析性能。基于DL-Ti₃C₂纳米片独特的二维纳米片形态、大的比表面积和优异的导电率，所制备的传感器能够实现对多巴胺的高灵敏检测，检出限为0.33μmol/L。该传感平台可用于针对飞行员的特殊神经精神性疾病检测。     

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.