时间分辨后化学发光同时测定林可霉素和卡那霉素

根据林可霉素、卡那霉素在过氧化单硫酸盐(PMS)-鲁米诺(Luminol)体系中的化学发光反应动力学性质的明显差异,建立了时间分辨后化学发光同时测定林可霉素和卡那霉素的新方法.在PMS-鲁米诺体系中林可霉素化学发光反应较快,0.8s达到最大值,峰尖锐;卡那霉素化学发光反应较慢,54.8s后达到最大值,峰平缓,且其动力学曲线呈现出随时间分开的两个独立的发光峰,互不干扰.该方法测定林可霉素、卡那霉素的线性范围分别为4.0×10-9～8.0×10-7 g/mL、4.0×10-7～8.0×10-5 g/mL,对8.0×10-8 g/mL的林可霉素溶液和8.0×10-6 g/mL的卡那霉素溶液进行测定,其相对标准偏差(RSD,n=11)分别为4.6％和3.3％,测定林可霉素和卡那霉素的检出限分别为1.0×10-9 g/mL和1.0×10-7 g/mL.     

流动注射后化学发光法测定异烟肼

本文发现了异烟肼在铁氰化钾-钙黄绿素化学发光反应体系中的后化学发光反应。优化了反应条件,建立了一种利用后化学发光反应测定异烟肼的流动注射化学发光分析法。方法的检出限为6×10-8g/mL, 相对标准偏差为1.8% (2.0×10-6 g/mL 异烟肼,n=11）,线性范围为2.0×10-7~1.0×10-5 g/mL。此法已用于异烟肼片剂中异烟肼含量的测定,结果与药典方法测定值一致。     

流动注射胶束化学发光法测定西咪替丁的研究

在碱性条件下K3Fe(CN)6可直接氧化西咪替丁产生化学发光信号,吐温-80的存在可大大增强此反应的化学发光强度。基于此,建立了胶束流动注射化学发光法测定西咪替丁的新方法。在优化的实验条件下,该法的线性范围为1.0×10-7~5.0×10-4g/mL,检出限为2×10-8g/mL,相对标准偏差为1.6%(n=11,ρ=5.0×10-7g/mL)。该法已用于西咪替丁制剂中西咪替丁的测定。     

铁氰化钾-鲁米诺体系后化学发光行为的研究-流动注射后化学发光法测定可待因

发现了可待因在铁氰化钾鲁米诺化学发光反应体系中的后化学发光反应。优化了反应条件,建立了一种利用后化学发光反应测定可待因的流动注射化学发光新方法。方法的检出限为3×10-8g mL,相对标准偏差为1.9%(1.0×10-6g mL可待因,n=11),线性范围为8.0×10-8～1.0×10-5g mL。此法已用于可待因片剂中可待因的测定,结果与药典方法测定值一致。     

流动注射化学发光法测定安痛定注射液中的氨基比林

在甲醛存在下 ,高锰酸钾与氨基比林能够发生化学发光反应 ,产生很强的化学发光 ,据此采用流动注射技术建立了一种测定氨基比林的化学发光分析法。方法的检出限为 3 .0× 10 -8g/mL ,相对标准偏差为 1.3 % (4 .0× 10 -6g/mL氨基比林 ,n =11) ,线性范围为 1.0× 10 -7～ 8.0× 10 -5g/mL氨基比林。该法已用于安痛定注射液中氨基比林含量的测定。     

流动注射电化学发光法测定头孢氨苄

根据在强酸性介质中初生态Mn(Ⅲ)直接氧化头孢氨苄产生强化学发光,将在线恒电流电解产生Mn(Ⅲ)与流动注射技术结合,建立了流动注射电化学发光测定头孢氨苄的新方法。在优化的实验条件下,测定头孢氨苄的线性范围为1.0×10-7~6.0×10-5g/mL,检出限为5×10-8g/mL,相对标准偏差为1.8%(c=5.0×10-6g/mL,n=11)。方法简便快速,用于头孢氨苄胶囊中头孢氨苄含量的测定,结果满意。     

无机偶合流动注射化学发光测定钛的研究

基于钛(Ⅲ)对铬(Ⅵ)氧化I-产生I2的诱导作用,和I2氧化鲁米诺产生化学发光的反应,建立了无机偶合反应流动注射化学发光测定痕量钛的新方法。方法线性范围为1×10-9～1×10-5g/mL,RSD=3.0%(n=11,ρ=1×10-7g/mL),检出限为4.0×10-10g/mL。方法用于人发样品中钛的测定。     

家兔血液中西咪替丁的微透析-毛细管电泳测定研究

本文报道用微透析毛细管电泳测定家兔血液中的西咪替丁。研究发现,采用如下条件:100mmol/LpH2.5的磷酸盐缓冲液,分离电压17kV,电动进样9kV×9s,西咪替丁与雷尼替丁能达到基线分离,据此以雷尼替丁为内标建立了一种测定西咪替丁的方法。西咪替丁与雷尼替丁峰面积比与相应的西咪替丁浓度在8.0×10-9～4.0×10-7g/mL范围内呈线性关系(r=0.998),检出限为5.0×10-9g/mL。药物代谢动力学参数由“NDST21”计算软件求得,代谢符合一室开放模型。     

铁氰化钾-鲁米诺体系后化学发光反应及其分析应用研究-分子印迹-后化学发光法测定双嘧达莫

研究了双嘧达莫在铁氰化钾-鲁米诺化学发光反应体系中的后化学发光反应, 并在研究其反应的动力学性质、化学发光光谱、荧光光谱以及一些相关问题的基础上, 探讨了反应机理; 合成了双嘧达莫的分子印迹聚合物, 以此聚合物为分子识别物质, 利用铁氰化钾-鲁米诺-双嘧达莫后化学发光体系, 建立了测定双嘧达莫的高选择性分子印迹-后化学发光分析方法. 所建方法的线性范围为1.0×10-8-1.0×10-6 g/mL(r=0.999 2), 检出限为3×10-9 g/mL, 相对标准偏差为2.7%(1.0×10-7 g/mL双嘧达莫, n=11).     

流动注射化学发光法测定褪黑素

在强碱性介质中,铁氰化钾可直接氧化褪黑素产生化学发光。基于此,建立了一种测定褪黑素的流动注射化学发光分析方法。线性范围为1.9×10-6~2.3×10-4g/mL,检出限为5×10-7g/mL,该法已用于药物中褪黑素的测定。     

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.