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101.
《Analytical letters》2012,45(5):1047-1055
Abstract An amperometric enzyme modified carbon paste electrode for the detection of xanthinc by the xanthine oxidase catalyzed reaction is described. the product of the enzyme reaction monitored is the highly unstable radical superoxide, detected at O mV (vs SCE) poised potential. A dual working electrode configuration consisting of an enzyme modified carboa paste electrode and an unmodified glassy carbon electrode are utilized for this purpose. 相似文献
102.
Bing Chen Liang Chen Li‐Jun Gao Su‐Yu Ye Rui Xiao Pei‐Lian Liu Bi‐Lian Chen Yun‐Xia Zhang Jun Yao 《中国化学会会志》2012,59(4):520-524
A superoxide dismutase enzyme was extracted from the leaves of Agave Hybrid No.11648 using homogenisation, ammonium sulphate fractional precipitation, diethylaminoethyl cellulose ion exchange and Sephadex gel filtration chromatography. A superoxide dismutase parallelogram‐shaped crystal was formed after packing at 4 °C for two days. The optimum pH was 8, and the optimum temperature was 40 °C. The crystal was relatively stable at temperatures below 60 °C and at pH values from 5 to 10. The subunit size was determined to be approximately 27.5 kDa by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis. It was also demonstrated that the enzyme is an iron‐containing superoxide dismutase based on its sensitivity to inhibitors of potassium cyanide, hydrogen peroxide and chloroform‐ethanol and based on the results of ultraviolet absorption spectroscopy. 相似文献
103.
104.
《Journal of Coordination Chemistry》2012,65(3):515-523
Two new isostructural copper(II)–zinc(II) complexes, [CuZnLBr2] (1) and [CuZnLCl2] (2) (H2L = N,N′-bis(4-methoxysalicylidene)cyclohexane-1,2-diamine), have been synthesized and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray diffraction. Both complexes crystallize in the P-1 space group. The Cu in each complex is four-coordinate square planar with two imines and two phenolates of L. The Zn in each complex is four-coordinate tetrahedral with two phenolates of L and two halides (Br for 1 and Cl for 2). The superoxide dismutase (SOD) activity of the complexes indicates that both complexes are rudimentary models for SOD. 相似文献
105.
《Journal of Coordination Chemistry》2012,65(22):3926-3938
An unexpected mononuclear Ni(II) complex, [Ni(L2)2]·CH3OH (HL2 = 1-(2-{[(E)-3,5-dichloro-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), has been synthesized via complexation of Ni(II) acetate tetrahydrate with HL1. HL1 and its corresponding Ni(II) complex were characterized by IR, 1H-NMR spectra, HRMS, as well as by elemental analysis, UV–vis, and emission spectroscopy. The crystal structure of the complex has been determined by single-crystal X-ray diffraction. Each complex links two other molecules into an infinite 1-D chain via intermolecular hydrogen bonds. Moreover, the electrochemical properties of the nickel complex were studied by cyclic voltammetry. Superoxide dismutase-like activities of HL1 and Ni(II) complex were also investigated. 相似文献
106.
Montserrat Cortina-Puig Xavier Muoz-Berbel Regis Rouillon Carole Calas-Blanchard Jean-Louis Marty 《Bioelectrochemistry (Amsterdam, Netherlands)》2009,76(1-2):76
This paper describes the development of an amperometric cytochrome c (cyt c)-based biosensor and its later application to the quantification of the scavenging capacity of antioxidants. The enzymatic biosensor was constructed by covalently co-immobilizing both cyt c and XOD on a mercaptoundecanol/mercaptoundecanoic acid (MU/MUA) mixed self-assembled monolayer (SAM)-modified screen-printed gold electrode. The applicability of this method was shown by analyzing the antioxidant capacity of pure substances, such as ascorbic acid and Trolox, and natural sources of antioxidants, particularly 5 orange juices. 相似文献
107.
Hakim Karoui 《Tetrahedron letters》2004,45(5):1043-1045
In phosphate buffer solution the half-life of the PBN-superoxide spin adduct is very short. However, as a result of the formation of inclusion complexes, its ESR signal was easily detected for up to 25 min when the trapping of superoxide anion with PBN was carried out in the presence of different cyclodextrins. Furthermore, the formation of these inclusion complexes results in a significant protection of the PBN-superoxide adduct against l-ascorbate monoanion reduction. 相似文献
108.
The capacity of estrogen and stilbene derivatives to modulate the activity of superoxide dismutases in relation with their estrogenic properties has been studied. The properties of trans-resveratrol (3,5,4′-trihydroxystilbene) and its analogues, 4-hydroxystilbene, 4,4′-dihydroxystilbene, 3,5-dihydroxystilbene, 3,5,4′-trimethoxystilbene and 4,4′-dihydroxy-3,5,3′,5′-tetramethylstilbene were compared to 17β-estradiol and its analogues (2-methoxyestradiol, estrone, 2-hydroxyestradiol and 2-methoxyestrone). Measurement of estrogen receptor-β (ER-β) binding capacity was carried out by a receptor competitor assay associated with fluorescence polarisation detection. The superoxide dismutase (SOD) modulation activity was followed with a spectrophotometric assay using the sequence xanthine/xanthine oxidase-2,3-bis[2-methoxy-4-nitro-sulfo-phenyl]-2H-tetrazolium-5-carboxanilide (X/XO-XTT). The structure-activity relationship was different for the two series tested. In the estrogenic series, a compound which does not inhibit SOD, is recognized by the ER-β. In contrast for the stilbenic series both properties are parallel each other. 相似文献
109.
分析了可见光/H2O2体系中产生协同敏化效应的原因. 通过分析苯酚红、 甲基橙、 天青Ⅰ及三者混合物的紫外-可见光谱发现, 三者混合后拓宽了在可见光区的响应范围, 提高了对可见光的利用率. 采用邻菲罗啉法、 二苯基卡巴肼法和磷钼酸铵分光光度法分别测试了上述有色物在可见光/H2O2体系中产生光生电子e、 单线态氧和超氧阴离子自由基的量, 结果表明, 三者混合物在可见光下超氧阴离子自由基的产量明显比单独有色物的高, 光生电子和单线态氧的产量相差不大, 说明超氧阴离子自由基产量的提高是产生协同敏化的主要原因. 测试结果还证实光生电子不能催化过氧化氢产生羟自由基. 相似文献
110.
SU Yan-bin JIANG Yi-zhong LU Ming CHENG Ying-kun SU Yan-wen ZHANG Fen-rong LI Zheng-qiang . Key Laboratory for Molecular Enzymology Engineering the Ministry of Education Jilin University Changchun P. R. China . School of Chemical Pharmaceutical Engineering Jilin Institute of Chemical Technology Jilin . Jilin Provincial Institute for Drug Food Control Changchun . Cardiovascular Surgery 《高等学校化学研究》2009,25(5):686-689
Effect of Siqi decoction on myocardial ischemia is to prevent cardiac myocyte membrane from damage associated with oxygen free radicals related to NO. To research the regulatoin of the content of malondialdehyde by Siqi decoction, an index of lipid peroxidation, via increasing activity of superoxide dismutase in blood serum of rats with Myocardial Ischemia, the model of myocardium ischemia was made in Wistar rats with posterior pituitary injection through vein in tail. Siqi decoction, Diaoxinxuekang(DK) and... 相似文献