洛美沙星在胶束体系中的荧光特性研究及应用

研究了洛美沙星在胶束中的荧光特性,发现十二烷基磺酸钠(SDS)对洛美沙星的荧光有较强的增敏作用。据此,提出了胶束增敏荧光光谱法测定痕量洛美沙星的新方法,洛美沙星含量在0.04~4μg/mL范围内与其荧光强度线性关系良好,相关系数r=0.9995。方法的平均回收率为96.2%~100.8%。     

胶束增敏荧光法测定锆

在CTAB胶束介质中配合物组成可发生一系列变化,这是其对吸光度及荧光增敏的决定因素。在合适的CTAB浓度下,可形成Zr(Ⅳ):Morin=1:3的高次配合物,使体系的摩尔吸光系数增加3倍多;但随着CTAB浓度的增大,形成了Zr(Ⅳ):Morin:SO₄^2-=1:1:2的混配配合物,硫酸根起了辅助配体的作用,荧光强度增强数十倍,稳定性也有很大提高,对CTAB胶束改变配合物组成及增敏荧光的原因进行了研究。据此建立了胶束增敏荧光测定锆的新方法。该法的检测下限为0.2ng/mL,线性范围为0.2ng/mL～0.5μg/mL,选择性、稳定性均好。     

胶束增敏法测定盐酸左氧氟沙星的研究

研究了盐酸左氧氟沙星（OFLX）在胶束体系中的荧光性质,发现十二烷基硫酸钠对OFLX有较强的增敏作用,据此建立了胶束增敏荧光光谱法测定痕量OFLX的新方法。其线性范围为0～1．00μg/mL,检出限为4．73ng／mL。     

Cu(Ⅱ)-头孢羟氨苄的荧光光谱性质及应用

采用不同的表面活性剂对Cu(Ⅱ)与头孢羟氨苄生成的配合物在胶束体系中的荧光性质进行了研究,发现在pH6.2的Tris缓冲溶液中阴离子表面活性剂十二烷基硫酸钠对其配合物的荧光有显著的增敏作用,据此建立了胶束增敏荧光光谱法测定头孢羟氨苄的新方法。在最佳实验条件下其线性范围为0.03~1.14μg/mL,检出限为0.03μg/mL,经实际样品测定,其平均回收率为97.3%~101.4%,相对标准偏差为1.1%~1.3%。     

反相胶束介质对2,3-二氨基吩嗪的荧光增敏作用研究

研究了反相胶束介质丁二酸双(2-乙基己基)酯磺酸钠(AOT)/正辛烷(n-octane)对漆酶催化氧化邻苯二胺的产物2,3-二氨基吩嗪(DAP)光谱性质的影响.试验表明,AOT/n-octane对DAP吸光性质稍有增敏作用,而对其荧光具有强烈的增敏作用,使DAP荧光量子产率提高近30倍,并进一步研究了微环境对荧光性质的影响和反相胶束介质AOT/n-octane对DAP荧光的增敏机理.     

胶束增敏荧光光谱法测定吡哌酸

采用不同表面活性剂对吡哌酸在胶束体系中的荧光性质进行了研究，发现在酸性介质中十二烷基硫酸钠(SDS)对吡哌酸有较强的增敏作用，据此建立了胶束增敏荧光光谱法测定吡哌酸的新方法。方法线性范围为0．07-0．36μg／mL，检出限为0.04μg／mL，平均回收率为98．6％-101．3％，相对标准偏差为1．1％-1．2％。样品测定结果令人满意。     

钯-柠檬黄-表面活性剂荧光光度法的研究与应用

本文研究了在各种类型的表面活性剂存在下, 钯与柠檬黄的胶束增敏荧光反应, 测定了金属荧光配合物的形成条件、组成、量子产率、表观稳定常数和激发波长处的摩尔吸光系数, 对胶束增敏作用机理进行了初步探讨. 确定了测定钯的最佳条件, 钯在0.1-8.0μg/25mL 范围内与荧光强度呈线性关系, 检出下限达8.0x10^-^4μg/mL. 本文方法可不经分离直接快速地测定贵金属矿样中痕量钯,结果令人满意。     

以恩诺沙星为检测对象探究恩诺沙星与牛血清白蛋白的相互作用

在模拟生理条件下,分别以蛋白为检测对象和以药物为检测对象,用荧光光谱法研究了不同温度下恩诺沙星(EFLX)与牛血清白蛋白(BSA)之间的相互作用。以两种不同分子作为检测对象均表明EFLX与BSA的猝灭方式为静态猝灭,作用力类型以疏水作用为主。基于实验进行了计算,获得了以EFLX为检测对象所得的结合常数远大于以BSA为检测对象的结合常数。这表明以药物为检测对象的荧光光谱法能更准确、更全面地传达药物与蛋白的相互作用信息。这个结论的正确性得到了紫外光谱法的验证。此外,考察了离子强度对EFLX-BSA体系的影响,通过EFLX与曙红B(EB)、盐酸柔红霉素(DH)、赫斯特荧光染料(Hoechst)的竞争实验,推测了EFLX与BSA的结合方式为沟槽式。     

诺氟沙星在胶束溶液中的荧光光谱特性及其应用

诺氟沙星在pH值为2.1的酒石酸-酒石酸钠缓冲溶液中具有较强的荧光,十二烷基磺酸钠(SDS)胶束溶液对诺氟沙星的荧光有增敏作用,线性范围为0.069 3~0.693 0μg/mL,回归方程为F=66.89c 0.149 4,相关系数为0.999 4,检出限为0.010 3μg/mL。用该法测定滴眼液和胶囊中诺氟沙星的含量,相对标准偏差为0.10%~0.93%,回收率为90.91%~108.5%。     

荧光分析法测定荜茇有效成分荜茇宁

根据荜茇有效成分荜茇宁的荧光被表面活性剂OP-10显著增敏的特征,提出了胶束增敏荧光法测定蒙药荜茇中荜茇宁的荧光分析新方法.荜茇宁的含量在2.0～16.0μg/mL范围内,与其荧光强度呈良好的线性关系,相关系数为0.9992,方法的回收率为96.9%～104.5%.此方法适合蒙药荜茇中荜茇宁的测定.     

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%.     

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.     

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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.