银微盘电极上头孢氨苄降解产物的伏安行为及其应用

基于头孢氨苄降解产物中含有巯基，能与Ａｇ＾＋生成难溶化合物的特性，在银微盘电极上研究了ＣＥＸ降解产物的伏安行为，探讨了电极反应的机理。运用示差脉冲溶出伏安法，在０．１ｍｏｌ／Ｌ ＨＡｃ－ＮａＡｃ介质中，ＣＥＸ降解产物的还原峰电流与ＣＥＸ浓度于８．０×１０＾－８－７．０×１０＾－６ｍｏｌ／Ｌ范围内呈良好线性关系；检测限为１．０×１０＾０８ｍｏｌ／Ｌ；测定了头孢氨苄胶囊中ＣＥＸ含量为９２．０％，与药典     

头孢噻肟钠的降解及其产物伏安行为的研究

头孢噻肟钠在ＮａＯＨ溶液中降解后，于０．１ｍｏｌ／ＬＮａＯＨ中得一灵敏的吸附伏安原峰，Ｅｐ＝－０．７８Ｖ（νｓＡｇ／ＡｇＣｌ），ｉｐ与头孢噻肟钠浓度在１．０×１０＾－＾９－１．０×１０＾－＾８，１．０×１０＾－＾８－１．０×１０＾－＾７，１．０×１０＾－＾７－１．０×１０＾－＾６ｍｏｌ／Ｌ范围内呈线性关系，检出限为５．０×１０＾－＾１＾０ｍｏｌ／Ｌ。用多种电化学手段研究其降解产物的伏安行为，测定了     

铕—敌鼠—DL—组氨酸—十六烷基三甲基溴化铵荧光体系及其应用

研究了铕－敌鼠－ＤＬ－组氨酸－ＣＴＭＡＢ荧光体系的荧光特性，测定了体系的影响因素和测定敌鼠的实验方法，体系的激发和发射波长分别为３３０ｎｍ和６１２ｎｍ，各组分的最佳浓度分别为１．０×１０＾－５ｍｏｌ／Ｌ，ＤＬ－组氨酸，１．０×１０＾－４ｍｏｌ／Ｌ，ＣＴＭＡＢ１．０×１０＾－５ｍｏｌ／Ｌ，ｐＨ为９．０，在此条件下，敌鼠浓度在６．０×１０＾－７～９．０×１０＾－５ｍｏｌ／Ｌ范围内同体系的荧光强度成线性     

高锰酸钾—抗坏血酸化学发光体系测定抗坏血酸

本文研究了高锰酸钾－抗坏血酸化学发光体系，建立了测定抗坏血酸的化学发光分析新方法，线性响应的浓度范围为５．０×１０＾－７ｍｏｌ／Ｌ～４．０×１０＾－５ｍｏｌ／Ｌ，检出限为３．０×１０＾－７ｍｏｌ／Ｌ，对２．５×１０＾－６ｍｏｌ／Ｌ抗坏血酸进行１０次平行测定，相对标准偏差为１．６％，考察了２２种物质的干扰情况。用于维生素Ｃ片剂及注射液中抗坏血酸含量测定，结果令人满意。     

浸蜡石墨电极伏安法测定抗癌药物盐酸阿霉素

本用自制浸蜡光谱纯石墨电极伏安法测定盐酸阿霉素。在ＰＨ＝６．０的磷酸缓冲溶液体系中，盐酸阿霉素在５．０×１０＾－８ｍｏｌ／Ｌ－１．０×１０＾－６ｍｏｌ／Ｌ范围内浓度与电流呈线性检测限可达１．０×１０＾－８ｍｏｌ／Ｌ。方法选择性好，抗干扰能力强，不需样品分离可直接进行测定。结果令人满意。     

钼—桑色素的极谱波及其用于钨精矿中钼的测定

本提出了测定钼的新极谱体系，最佳底液条件为ｐＨ２．１的盐酸－２．３７×１０＾－６ｍｏｌ／Ｌ桑色素－０．１７２ｍｏｌ／Ｌ氯酸钠。极谱波峰电位为－０．４３Ｖ（ｖｓ．ＳＣＥ），钼（Ⅵ）浓度在１．０４×１０＾－９￣４．５９×１０＾－８ｍｏｌ／Ｌ范围内与波高有线性关系，检出限３．６７×１０＾－１０ｍｏｌ／Ｌ。方法简便，快速、准确，并已直接应用于钨精矿中微量钼的测定。     

阿霉素在钴离子注入修饰电极上的电化学行为及其应用

阿霉素在０．１ｍｏｌ／Ｌ ＨＡｃ－ＮａＡｃ（ｐＨ４．６２）缓冲溶液中用注入钴的修饰玻碳电极为工作电极进行伏安测定,得到一良好的还原峰;Ｅｐ＝－０．５２２Ｖ（ｖｓ．ＳＣＥ）。峰电流与阿霉素浓度在１．４×１０＾－６－１．４×１０＾－６ｍｏｌ／Ｌ和１．４×１０＾－６－５．６×１０＾－５ｍｏｌ／Ｌ范围内呈线性关系,。     

头孢哌酮钠的伏发行为及其应用研究

头孢哌酮钠在０．０５ｍｏｌ／Ｌ Ｈ２ＳＯ４溶液中,形成一良好的示波极谱导数峰。峰电位为－０．８２Ｖ（ｖｓ．ＳＣＥ）。峰电流与头孢哌酮钠的浓度在１．０×１０＾－７－２．０×１０＾６ｍｏｌ／Ｌ范围内成线性关系。检出限为５．０×１０＾－８ｍｏｌ／Ｌ。回收率在９４．０％－１０２．０％之间。并用于尿样的测定,得到满意的结果。     

四磺基铁酞菁做为过氧化物模拟酶在过氧化氢及葡萄糖测定中的应用

以四磺基铁酞菁（ＦｅＴＳＰｅ）作为过氧化物模拟酶催化Ｈ２Ｏ２与Ｌ－酪氨酸的荧光反应,建立了测定宽含量范围的Ｈ２Ｏ２及葡萄糖的方法。该法的线性范围为０．０－８．０×１０＾５ｍｏｌ／Ｌ,Ｈ２Ｏ２及０．０￣２．０×１０＾－４ｍｏｌ／Ｌ葡萄糖,检测限分别为５．０×１０＾－８ｍｏｌ／Ｌ及６．０×１０＾－６ｍｏｌ／Ｌ,将该经酶催化反应偶联,测定人血清中葡萄糖的含量,取得了满意的结果。     

酮康唑在玻碳电极上的吸附行为及其测定

报道了一种抗真菌治疗新药酮康唑的吸附行为及其测定。该药物在玻碳电极上预富集后，用示差脉冲伏安法测定，其响应电流与药物浓度在２．０×１０＾－１０－１．０×１０＾－－５ｍｏｌ／Ｌ范围内呈线性关系；检屈限为４．０×１０＾－１１ｍｏｌ／Ｌ。可用于尿和血清样品中药物含量的测定。     

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%.     

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.     

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.     

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.