基于适体生物传感器的碱性磷酸酯酶化学发光检测腺苷

制备了一种可用于腺苷检测的适体生物传感器,以羧基磁性微球为载体,在其表面组装腺苷适体与地高辛修饰之腺苷适体互补的核酸短链,先加入一定浓度的腺苷,再连接抗地高辛的碱性磷酸酯酶,用化学发光法检测发光值,根据腺苷加入前后化学发光强度的变化来定量检测腺苷。实验考察了羧基磁性微球用量、氨基修饰的腺苷适体用量、地高辛修饰的核酸短链用量及抗地高辛的碱性磷酸酯酶用量对体系组装和腺苷识别的影响。结果显示,优化条件下,在1.0×10~(-7)~1.0×10~(-3)mol/L范围内,腺苷浓度的对数与发光信号呈线性关系(r~2=0.976 9),定量下限为1.0×10~(-7)mol/L。与其他核苷相比,腺苷的选择特异性更好,且在稀释血清中适体对腺苷有很好的特异性识别能力。     

基于多边形金纳米颗粒的非标记型可卡因适体传感器的研制

实验合成了多边形金纳米颗粒,通过壳聚糖(CHIT)将合成的多边形金纳米颗粒固定在玻碳电极表面,然后通过自组装技术将带巯基的捕获DNA探针固定在修饰有多边形金纳米颗粒的电极表面,利用杂交反应使可卡因适体与DNA捕获探针结合,制成非标记型可卡因适体传感器。以六氨合钌作为电化学指示剂,通过测量传感器与目标物可卡因结合前后电流变化情况对可卡因进行测定。考察了缓冲溶液的pH、可卡因培育时间、扫描速度等对测定的影响。结果表明,在pH为7.40时该传感器的检测范围为1.0×10-10～1.0×10-3 mol/L,检测限为3.0×10-11 mol/L。该传感器制作简单,响应好,抗干扰能力强。     

基于核酸适配体的化学发光检测腺苷

以羧基磁性微球为分离载体,固定氨基修饰的腺苷适配体,通过腺苷与生物素修饰的报告序列竞争结合氨基适配体,建立了一种化学发光检测生物小分子腺苷的方法。实验优化了磁性微球、氨基适配体、报告序列等参数,发现腺苷浓度在1.0×10-9~1.0×10-4mol/L范围内与CL信号强度减少量呈良好线性关系,最低检出限达1.0×10-9mol/L,重复5次测定0.1 mmol/L腺苷的相对标准偏差为5.0%。方法成功用于实际尿样中腺苷的测定。该法可简单、灵敏、特异性地检测腺苷,有望用于临床诊断、药物分析等领域。     

基于磁性分离-硫化铜纳米粒子标记的DNA流动注射化学发光检测

本文基于磁性粒子(MB)良好的分离、富集能力,研究了硫化铜纳米粒子标记的流动注射-化学发光(FI-CL)DNA检测体系.通过硫化铜标记的探针1与目标DNA及连有磁球的探针2形成三明治结构,实现对目标DNA的捕获、分离与标记;通过其溶解释放出CuS标记颗粒的铜离子,引起化学发光信号增强,实现了目标DNA序列的定性定量检测.该方法对完全互补单链DNA(ssDNA)检测的线性范围为1.0×10-11～1.6×10-9 mol/L,检出限为3.0×10-12 mol/L,对1.0×10-9 mol/L目标DNA测定的相对标准偏差为3.2%(n=11),对目标碱基序列具有良好的识别能力.     

基于核酸适配体的化学发光检测腺苷

以羧基磁性微球为分离载体,固定氨基修饰的腺苷适配体,通过腺苷与生物素修饰的报告序列竞争结合氨基适配体,建立了一种化学发光检测生物小分子腺苷的方法。实验优化了磁性微球、氨基适配体、报告序列等参数,发现腺苷浓度在1.0×10-9~1.0×10-4 mol/L范围内与CL信号强度减少量呈良好线性关系,最低检出限达1.0×10-9mol/L,重复5次测定0.1 mmol/L腺苷的相对标准偏差为5.0%。方法成功用于实际尿样中腺苷的测定。该法可简单、灵敏、特异性地检测腺苷,有望用于临床诊断、药物分析等领域。     

金标记羟胺放大化学发光检测赭曲霉毒素A

以羧基磁性微球为分离载体,连接氨基捕获探针和适配体,加入生物素化报告序列和赭曲霉毒素A(Ochratoxin A,OTA)竞争结合适体,继续加入链霉亲和素纳米金和羟胺/Au~(3+)以显著提高化学发光检测OTA的灵敏度,从而建立了一种纳米金标记羟胺放大化学发光检测OTA的高灵敏度方法。优化了羧基磁性微球、氨基捕获探针、适配体、生物素化报告序列、链霉亲和素纳米金的用量。优化条件下,在OTA质量浓度0.01~50 ng/m L范围内,化学发光信号值与OTA浓度的对数呈较好的线性关系(r~2=0.992 5),检出限为1.58×10~(-3)ng/mL。对啤酒样品进行OTA加标回收实验,回收率为97.4%~105.4%,相对标准偏差为4.0%~5.5%。     

流动注射化学发光法测定废水中Mn(Ⅱ)

鲁米诺与K2S2O8在碱性介质中能产生稳定的化学发光信号,Mn2+对鲁米诺过硫酸钾体系的化学发光产生微弱的抑制作用,而Ag+能增强Mn2+对发光体系的抑制作用,据此建立测定了废水中微量Mn2+的流动注射化学发光分析方法。Mn2+的浓度在1.0×10-10～1.0×10-7mol/L范围内与相对发光强度(ΔI)呈良好的线性关系,检出限为1.0×10-12mol/L;对1.0×10-7mol/LMn2+进行11次平行测定,其相对标准偏差RSD为1.3%。方法已用于测定废水中Mn2+的含量。     

KMnO4-乙二醛化学发光法测定苦味酸

基于苦味酸对KMnO4-乙二醛化学发光体系的抑制作用,建立了苦味酸的流动注射化学发光测定方法;在最佳条件下,方法对苦味酸的检出限为1.0×10 -12 mol/L,线性范围为1.0×10-11～1.0×10 -3 mol/L;对1.0×10-7 mol/L苦味酸平行测定11次,其RSD为2.5％.该方法可应用于水样中的...     

流动注射化学发光法测定中药材中没食子酸

建立快速简便的流动注射化学发光分析法,用于中药材中没食子酸含量的测定.利用酸性介质中Fe3+-H2O2体系生成羟基自由基氧化没食子酸产生微弱的化学发光,用罗丹明6G来增敏化学发光.研究了影响化学发光的各种因素,探讨了可能的机理.结果表明,0.18 mol/L HCl,0.04 mol/L FeCl3,1.0 mol/L H2O2与1.0×10-4 mol/L罗丹明6G溶液组成最优的化学发光体系,没食子酸浓度在1.0×10-5～1.0×10-2 g/L和0.01～1.0 g/L范围内与化学发光强度呈很好的线性关系,r分别为0.9984和0.9947,检出限为3.0×10-6 g/L.对1.0×10-4 g/L没食子酸平行测定11次的相对标准偏差为3.8%.利用本方法成功地测定了中药材诃子和没食子中的没食子酸含量.     

鲁米诺-过氧化氢化学发光体系测定酪氨酸

碱性条件下,H2O2氧化鲁米诺产生化学发光,酪氨酸对该体系的化学发光信号具有显著的抑制作用。据此建立了一种直接测定酪氨酸的流动注射化学发光分析新方法。该方法线性范围为4.0×10-7~2.0×10-5mol/L,检出限为1.0×10-7mol/L。对8.0×10-6mol/L的酪氨酸平行测定6次,其相对标准偏差为2.9%。该方法可应用于尿液中酪氨酸的测定。     

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.