四磺基锰酞菁作为过氧化物模拟酶在过氧化氢化学发光测定中的应用

以四磺基锰酞菁 (MnTSPc)作为过氧化物模拟酶催化H2 O2 与鲁米诺的化学发光反应 ,建立了测定环境样品中H2 O2 的化学发光分析新方法。该法的线性范围为 4 .0× 10 - 8～ 2 .0× 10 - 5mol L ;检出限为 6 .8×10 - 9mol L ;对 1.0× 10 - 6 mol L的H2 O2 进行连续 10次平行测定 ,相对标准偏差为 2 .4 %。用本法对天然雨水进行了分析测定 ,结果良好。     

流动注射-化学发光法测定盐酸林可霉素

盐酸林可霉素在 Na IO4 - H2 O2 - H+体系中能发生强的化学发光反应 ,据此建立了一种测定盐酸林可霉素的流动注射 _化学发光分析法 ,方法的检出限为 3.6× 1 0 -8g/m L,相对标准偏差为 1 .0 % (c S=1 .0× 1 0 -6g/m L,n=1 1 ) ,线性范围为 1 .0× 1 0 -7～ 9.0× 1 0 -5g/m L。该方法已用于盐酸林可霉素注射液的分析     

微阀进样和固定化试剂化学发光微流动注射芯片的研究

设计了一种将微注样阀和发光试剂均集成化的微流动注射化学发光芯片。利用luminolK3Fe(CN)6H2O2化学发光体系,研究了这种芯片的分析特性。该芯片测定H2O2的线性范围为2×10-5～8×10-9mol/L;检出限为3.6×10-9mol/L;相对标准偏差RSD=4.4%(c=1×10-6mol/L,n=11)。与常规的流动注射化学发光分析法相比,该芯片具有简单、快速、灵敏度高、耗样量少等特点,并结合酶促反应成功地用于人体血清中葡萄糖的测定。     

无机流动相低压离子色谱分离-化学发光在线检测痕量锰

以0.09 mol/L KCl和0.01 mol/L HCl的混合溶液作流动相,低压离子色谱(LPIC)分离,鲁米诺-H2O2化学发光(CL)在线检测Mn2+。研究了分离条件、化学发光条件及二者匹配方式和干扰离子等因素对分离和检测的影响。测定Mn2+的线性范围为1×10-9~4×10-8g/L,检出限为1×10-9g/L。该法用于测定血清、尿液、嘉陵江水样中的Mn2+。     

辣根过氧化物酶催化过氧化氢氧化隐性亮绿显色反应的研究

以隐性亮绿 (RBG)为氢供体底物 ,研究了辣根过氧化物酶 -H2 O2 -RBG显色反应体系的酶催化特性。在 p H 5.0～ 6.0的条件下反应形成的酶催化产物亮绿 (BG)于 63 0 .6nm处有最大吸收 ,该显色反应测定 H2 O2 的表观摩尔吸光系数为 5.64×1 0 4 L·mol- 1·cm- 1,线性范围为 3 .55× 1 0 - 8～ 6.0× 1 0 - 6 mol/ L,检出限为 3 .55×1 0 - 8mol/ L。方法用于雨水中痕量 H2 O2 的测定 ,结果满意     

流动注射-抑制化学发光测定多贝斯的方法研究

碱性条件下 ,多贝斯对铁氰化钾鲁米诺体系的化学发光有显著抑制作用 ,提出了一种用于多贝斯质量监测的流动注射 抑制化学发光分析方法。方法的线性范围为 1 .6× 1 0 - 5g/mL～ 2 .0× 1 0 - 7g/mL ;检测限 ( 3σ)为 4 4× 1 0 - 8g/mL ;RSD为 1 .5 % (c多贝斯=2 0× 1 0 - 7g/mL ,n =1 1 ) ;采样频率为 30 0次 /h。     

测定利血平的流动注射化学发光新体系

研究了利血平在酸性条件下与高碘酸钾和过氧化氢产生化学发光的行为 ,建立了高碘酸钾 -利血平 - H2 O2 - H2 SO4 流动注射化学发光新体系。利血平的浓度在 1 .0× 1 0 - 6～ 1 .0× 1 0 - 4g/m L范围内与化学发光强度呈良好的线性关系 ,检出限为 2 .7× 1 0 - 7g/m L。对 2× 1 0 - 5g/m L利血平进行 1 1次平行测定 ,得该法的相对标准偏差为 2 .63%。方法用于利血平片剂含量的测定 ,结果与药典法测得值一致     

反相流动注射化学发光法测定单宁

在碱性介质中 ,单宁对高碘酸钾氧化鲁米诺的化学发光反应有较强的增敏作用 ,据此建立了反相流动注射化学发光测定单宁的新方法 ,并研究了最佳反应条件。该方法快速、准确、线性范围宽 ,测定单宁的检出限为 1 .1 2× 1 0 - 9g/ m L,方法的线性范围为 2 .0× 1 0 - 8～ 6 .0× 1 0 - 6 g/ m L,对于 4.0× 1 0 - 6 g/ m L单宁 1 0次测定的相对标准偏差为 0 .79%。应用于中药五倍子、诃子中单宁的测定 ,结果满意     

流动注射化学发光法测定制剂和血浆中的盐酸多巴胺

在碱性介质中,盐酸多巴胺对鲁米诺-KIO4化学发光体系有明显的增强作用,据此,结合流动注射技术,建立了微量快速测定盐酸多巴胺的流动注射化学发光分析法。该法线性范围为0．1—100μg∥L,检出限0．02μg／L（3σ）;对1．0μg/L盐酸多巴胺11次平行测定,其相对标准偏差为2．9％。此法已成功地用于注射剂及血浆中盐酸多巴胺的分析。     

锰C-抗坏血酸甲醛-化学发光体系的研究

实验观察到锰 氧化抗坏血酸可以产生弱的化学发光 ,甲醛对这一化学发光反应有较强的增敏作用 ,据此建立了测定抗坏血酸的流动注射化学发光分析法。方法的检出限为 2× 1 0 -8mol/L抗坏血酸 ;线性响应范围为 6 .0× 1 0 -8～ 2 .0× 1 0 -5mol/L。对 1 .0× 1 0 -6mol/L的抗坏血酸进行 1 1次测定 ,相对标准偏差为 2 3%。该方法已成功应用于维生素C针剂和片剂中抗坏血酸含量的测定 ,结果与药典方法测得值一致     

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.     

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.     

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.     

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.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.