3-巯基丙酸修饰的CdTe量子点共振瑞利散射光谱法测定溶菌酶

以3-巯基丙酸为稳定剂,在水相中合成了3-巯基丙酸修饰的CdTe量子点(MPA-CdTe)。基于溶菌酶对该量子点的共振瑞利散射有增强作用,建立了一种快速检测溶菌酶的方法。在pH 6.1的B-R缓冲溶液中,量子点在波长312nm处的共振瑞利散射的增强与溶菌酶浓度呈线性关系,线性范围为0.07～10.0mg.L-1,检出限(3s/k)为0.02mg.L-1。方法应用于合成样品中溶菌酶的测定,并用标准加入法测得方法的回收率在93.5%～106.0%之间。     

溴百里酚蓝-蛋白质体系的共振瑞利散射光谱的研究及分析应用

基于蛋白质对溴百里酚蓝共振瑞利散射的增强作用,建立了一种测定蛋白质的方法.在酸性B-R缓冲溶液中,溴百里酚蓝在365 nm波长处的共振光散射增强与蛋白质浓度呈线性关系.对人血清白蛋白、牛血清白蛋白、γ-人球蛋白、卵白蛋白测定的线性范围分别为0.04～2.4,0.04～2.4,0.04～1.6,0.04～1.8 mg·L-1;相应的检出限分别为23.9,23.O,25.0,30.4μg·L-1.用于人血清、尿液中总蛋白质含量的测定,分析结果的RSD依次为1.5%和3.3%,且与考马斯亮蓝法的结果相符.     

双偶氮染料刚果红共振瑞利散射法测大观霉素

建立了测定痕量大观霉素的共振瑞利散射法。在pH 3.25的Tris-盐酸缓冲介质中,大观霉素与酸性双偶氮染料刚果红相互作用后使体系的共振瑞利散射强度(ΔIRRS)明显增强,在370 nm处的ΔIRRS最大。增强的共振瑞利散射强度ΔIRRS与0.015~0.33 mg·L-1范围的大观霉素呈良好的线性关系,方法的检出限(3Sb/S)为0.012mg·L-1。该法用于市售大观霉素药物及人尿中大观霉素含量的测定,结果满意。     

共振瑞利散射光谱法测定长春瑞滨

提出了测定痕量长春瑞滨(NVB)的共振瑞利散射(RRS)光谱法。在pH为2.2的BR缓冲体系中,NVB与曙红Y(EY)形成物质的量的比为1比1的离子缔合物,从而引起共振瑞利散射强度显著增强,其最大散射波长位于312nm。散射信号的增强(ΔIRRS)与NVB的质量浓度在0.06~3.0mg·L-1范围内呈线性关系,检出限(3σ)为1.7μg·L-1。方法应用于注射液和尿样中NVB的测定,加标回收率在99.8%~101%之间,测定值的相对标准偏差(n=5)在1.1%~2.2%之间。     

盐酸吖啶黄-脱氧核糖核酸反应体系的共振瑞利散射及其应用

研究了盐酸吖啶黄与脱氧核糖核酸(DNA)之间的共振瑞利散射(RRS)增强作用,提出了共振瑞利散射技术测定核酸的方法。在pH 6.4的B-R缓冲溶液中,盐酸吖啶黄与脱氧核糖核酸结合使溶液共振瑞利散射强度增强,其最大散射峰位于505 nm处,而在330 nm波长处有一稍弱的散射峰。DNA质量浓度在0.04~0.80 mg.L-1范围内,与RRS强度呈线性关系,检出限(3S/N)为0.023 mg.L-1。应用于测定合成样品中DNA含量并测得回收率为98.0%~104.0%。初步探讨了反应机理,盐酸吖啶黄与DNA间的相互作用包含有静电引力、π-π堆积力。     

吩噻嗪染料亚甲基蓝共振瑞利散射法测利福平

建立了测定痕量利福平的共振瑞利散射(RRS)法。在NaOH溶液中,利福平与亚甲基蓝相互作用后,共振瑞利散射显著增强,在371 nm处的ΔIRRS最强。利福平的质量浓度在0.20～1.65 mg.L-1范围内与△IRRS成正比,检出限(3Sb/S)为0.038 mg.L-1。该法可用于人体血液及市售利福平药物中利福平含量的测定,结果满意。     

三元缔合-共振瑞利散射测定奶粉中的Ca

建立了快速、准确测定奶粉中Ca的共振瑞利散射方法。在弱酸性Tris-盐酸介质中,Ca(Ⅱ)和表面活性剂十六烷基三甲基溴化铵与刚果红反应生成一种红色的三元离子缔合物,使共振瑞利散射(RRS)信号明显增强,并产生新光谱。最大共振瑞利散射峰位于371 nm,Ca(Ⅱ)的质量浓度在0. 004~0. 80 mg·L~(-1)范围内与体系的共振瑞利散射增强强度ΔIRRS呈线性关系,检出限为3. 1 ng·mL~(-1)。方法用于奶粉中Ca的测定,结果满意。     

氯霉素、甲砜霉素与曙红Y的共振瑞利散射光谱及应用

在pH 1.30的酸性介质中,曙红Y(EOSY)分别与氯霉素(CHP)、甲砜霉素(TAP)相互作用形成离子缔合物,使共振瑞利散射(RRS)显著增强并产生新的RRS光谱。CHP–EOSY体系的最大RRS峰位于313nm,线性范围为0.015～0.32 mg.L-1,检出限为0.013 mg.L-1;TAP–EOSY体系的最大RRS峰位于314nm,线性范围为0.018～0.39 mg.L-1,检出限为0.012 mg.L-1。据此发展了以曙红Y为探针,用共振瑞利散射法测定氯霉素、甲砜霉素的方法。方法简便快速,有较高灵敏度,可用于实际样品中氯霉素、甲砜霉素的测定。     

溴代十六烷基吡啶增敏共振瑞利散射法测定药物中的维生素B_1含量

在pH 6.38的三羟甲基氨基甲烷-盐酸缓冲溶液和溴代十六烷基吡啶存在下,维生素B_1与氯酚红结合生成的缔合物使共振瑞利散射显著增强并产生新的共振瑞利散射光谱,最大共振瑞利散射峰位于339nm处,维生素B_1的质量浓度在0.03~0.42mg·L~(-1)内与其对应的共振瑞利散射增强程度(ΔI/_(RRS))呈线性关系,检出限(3s/k)为0.004 2mg·L~(-1)。据此提出了溴代十六烷基吡啶增敏共振瑞利散射法测定药物中的维生素B_1的方法。应用此方法分析了维生素B_1药物,加标回收率在99.2%~102%之间,测定值的相对标准偏差(n=6)在2.1%~2.5%之间。     

基于硫堇反应的共振瑞利散射光谱法测定阴离子表面活性剂

在pH 2.36的B-R介质中,一定量的3种阴离子表面活性剂十二烷基苯磺酸钠(SD-BS)、十二烷基硫酸钠(SDS)和十二烷基磺酸钠(SLS)可与1.0×10-4 mol·L-1硫堇溶液1.0mL在总体积10mL中反应生成离子缔合物,产生共振瑞利散射光谱,在其最大共振光散射峰655nm波长处测定共振瑞利散射强度IRRS。SDBS、SDS和SLS的质量浓度分别在0.05～3.0,0.5～3.0,1.0～5.0mg·L-1范围内与样品及空白溶液的IRRS值之差ΔIRRS呈线性关系,方法的检出限(3S/N)分别为0.017,0.166,0.571mg·L-1。方法用于两个标准样品和两个环境水样中SDBS的测定,测定结果与认定值和亚甲蓝光度法测得结果相符。     

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%.     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

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.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.