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增强辣根过氧化物酶催化鲁米诺化学发光反应的新型增强剂四苯硼钠 总被引:10,自引:2,他引:10
报道了新型增强剂四苯硼钠对过氧化物酶催化鲁米诺-过氧化氢发光反应的增强作用,建立了流动注射化学发光测定或辣过氧化物酶(HRP)的新体系。用该体系测定HRP线性范围为1.0×10-12×1.2×10-13mol/L;检测限为0.6×10-13mol/L。对0.6×10-13mmol/L的 HRP进行11次平行测定,相对标准偏差为 1. 5%。 相似文献
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过氧化物模拟酶催化的苯基荧光酮氧化反应及其分析应用 总被引:4,自引:0,他引:4
在NH4Cl-NH4OH缓冲介质中,氯化血红素(Hemin)有显著的过氧化物模拟酶活性,催化过程化氢氧化苯基荧光酮褪色。本文探讨了反应机理,比较Hemin与天然酶催化性能,考察反应条件和共存物质影响,从而提出测定Hemin和过氧化氢的高灵敏分光光度法,线性范围分别为0 ̄3.0×10^-8mol/L和0 ̄1.2×10^5mol/L;检测限(3σ)分别为1.8×10^-10mol/L和1.4×10^7 相似文献
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砷在1.5×10^-4mol/L Co-0.1mol/L KCNS-1%抗坏血酸-0.7mol/L Na2SO4-4×10^-3mol/L NaBr介质中产生一灵敏催化波,峰电位为-1.1V。采用微分脉冲极谱法研究了各项实验条件,建立了直接测定硫中微量砷的方法。该法简便快速,结果满意。 相似文献
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聚邻苯二胺修饰电极抗坏血酸氧化酶生物传感器的研究 总被引:6,自引:0,他引:6
本文报道了聚邻苯二胺/抗坏血酸氧化酶生物传感器,用这种传感器测定人体血清中的抗坏血酸,线性范围在1.0×10^-4~2.5×10^-7mol/L之间,响应时间为7s,检测限为1.0×10^-8mol/L。该传感器具有选择性好、灵敏度高和响应时间短等特点。 相似文献
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醋酸纤维膜固定过氧化氢酶电极的研究 总被引:1,自引:0,他引:1
本将过氧化氢酶与经活化处理的醋酸纤维膜共价固定,并与氧电极偶合,研制成静态和流通二种过氧化氢生物电极。研究了醋酸纤维膜的活化、酶的固定化、测试介质等有关的实验条件和参数。测得静态和流通二种电极响应的线性范围分别为6.7×10^-5 ̄2.0×10^-3mol/L和1.3×10^-4 ̄1.0×10^-3mol/L。将电极用于实际试样中的回收率测定时,获得了较好的结果。 相似文献
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报道了一种新的L-氨基酸氧化酶电极,这种酶电极系由氨气敏电极和以氨基化玻璃布为载体的酶膜所组成;研究了固定化条件对酶膜活性的影响以及底物浓度、温度和pH对电极响应特性的影响。该电极在6.0×10^-5~4.0×10^-3mol/L的底物浓度范围内呈良好的线性关系,检测下限为5.0×10^-5mol/L。在最宜条件下,酶电极具有良好的稳定性。 相似文献
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酶联免疫吸附法直接测定血清雌二醇 总被引:20,自引:0,他引:20
本合成了3种不同载体蛋白的雌二醇抗原,研究了载体蛋白免疫原性对雌二醇抗体产生的影响。应用酶联免疫吸附分析法测定了血清中雌二醇,浓度范围为5-160ng/ml(1.8×10^-^8-5.9×10^-^7mol/L).RSD%小于10.%,检测限为1.97ng/ml,相当于98.5pg/孔(按空白平均值的二倍标准偏差计算)。另外,本还建立了一种用考马斯亮蓝G-250测定半抗原与蛋白结合比的方法,提 相似文献
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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%. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
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. 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
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. 相似文献
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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. 相似文献
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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 SN2 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. 相似文献
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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. 相似文献
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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. 相似文献