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1.
Catalytic hydrolysis of phosphate diester (BNPP) and plasmid DNA by mononuclear macrocyclic polyamine metal complexes 总被引:1,自引:0,他引:1
The activities of the catalytic hydrolysis of phosphate diester(BNPP)[bis(p-nitrophenyl)phosphate diester]and plasmid DNA (pUC18)by mononuclear macrocyclic polyamine metal complexes have been investigated in this paper.The results showed that the highest activity in hydrolysis of BNPP was obtained with 1e-Zn(Ⅱ)complex(composed of lipophilic group)as catalyst.The hydrolysis rate enhancement is up to 3.64×10~4 fold.These metal complexes could effectively promote the cleavage of plasmid DNA(pUC18)at physiol... 相似文献
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缬氨酸Schiff碱金属铜配合物(PBP-L-Val-Cu)是新合成的一类非酶类切割工具, 合成了4种类型样品分别为L-CH3 Cu, D-CH3 Cu, L-Ph Cu和D-Ph Cu. 以质粒DNA(pUC18)为材料,分别对这4种类型化合物进行核酸切割效率的研究, 得出适合的反应体系后, 通过琼脂糖凝胶电泳对反应不同时间后核酸切割产物进行检测, 最终分别得到每种化合物将超螺旋型DNA切割成为开环型DNA和直线型DNA的切割效率, 经比较得出L-CH3 Cu型的切割效率是最快的. 将直线型DNA切割产物用琼脂糖凝胶回收试剂盒进行回收, 得到的直线型切割产物可以在T4连接酶的作用下重新连接起来. 利用酶切法对切口进行检测, 结果表明, 切割作用是具有特异性的. 另外, 该化合物对质粒pNQ216也具有切割活性. 相似文献
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Ahmet Colak Ender Cekirge Serdar Karaböcek Aslıgül Küçükdumlu Nagihan Sağlam Ertunga Melek Col Rza Abbasoğlu 《Chemical Papers》2009,63(5):554-561
Nucleolytic activities of some new oxime-type ligand complexes were investigated by neutral agarose gel electrophoresis. Analysis
of the cleavage products in agarose gel indicated that all complexes used converted supercoiled pUC18 plasmid DNA to its nicked
or linear form. It was found that nucleolytic activities of the complexes depend on the complex concentration, reaction time
and the presence of a cooxidant (magnesium monoperoxyphthalate, MMPP) in the reaction mixture. However, the complexes cleaved
pUC18 plasmid DNA at all investigated pH values. Nucleolytic activities of complexes were investigated for different complex
concentrations (0.1–100 μmol L−1), pH values (6.0–10.0) and reaction times (0–60 min). Molecular modeling studies performed by the Hyperchem Software together
with DNA-binding studies showed that planar sites of the complexes intercalated into double stranded DNA. It can be concluded
that all oxime-type ligand complexes used can be evaluated as nuclease mimics. 相似文献
5.
N. Raman S. J. Raja J. Joseph A. Sakthivel 《Russian Journal of Coordination Chemistry》2008,34(11):842-848
Macrocyclic complexes of Cu(II), Ni(II), Co(II), and Zn(II)of a tetradentate Schiff base ligand derived from 3-benzalideneacetoacetanilide
and N-(2-aminoethyl)-1,3-ropanediamine were synthesized. The nature of the complexes and the geometry have been inferred from
their microanalytical data, magnetic susceptibility measurements, IR, UV-Vis, 1H NMR, ESR, and mass spectral techniques. The low electrical conductance of the complexes supports the neutral nature. Monomeric
nature of the complexes is assessed from their magnetic susceptibility values.The in vitro biological screening effects of the investigated compounds were tested against the bacteria E. coli, S. aureus, S. typhi, and K. pneumoniae by the well diffusion method using agar nutrient as the medium. A comparative study of minimum inhibitory concentration (MIC)
values of the Schiff base and its complexes indicate that the metal complexes exhibit higher antibacterial activity than the
free ligand and the control (streptomycin). The cyclic voltammetry method was used to probe the interaction of a Cu(II) complex
with pUC18 DNA. Information of the binding ratio and intercalation mode can be obtained from its electrochemical data. Cyclic
voltammetric measurements showed that the Cu(II) complex undergoes a reversible reduction at biologically accessible potentials.
From the study, it is understood that the copper complex prefers to bind with DNA in Cu(II) rather than Cu(I) oxidation state.
The DNA cleavage ability of the complexes was monitored by gel electrophoresis using supercoiled pUC18 DNA in tris-HCl buffer.
The text was submitted by the authors in English 相似文献
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合成了一类新型多羟乙基双核大环多胺La(III)配合物, 其结构经1H NMR, MS, 元素分析等表征. 通过紫外分光光谱法和琼脂糖凝胶电泳技术, 研究了双核大环多胺La(III)配合物催化双对硝基苯酚磷酸二酯的水解反应和对质粒DNA(pUC18)的催化水解作用. 结果表明: 双核大环多胺La(III)配合物可以有效催化双对硝基苯酚磷酸二酯水解和促进质粒DNA在生理条件下的水解裂解. 双对硝基苯酚磷酸二酯的水解速率提高了2.36×104倍. 讨论了配合物结构对水解反应的影响. 相似文献
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以一种1,4,7,10,13,16,19,22,25,28,31-十一氮杂2,5,8,11,14,17,20,23,26,29,32-十一酰基-环三十三烷的衍生物(CYC)为配体,在溶液中和Ce(Ⅲ,M)离子形成氮杂大环铈配合物(M-CYC)作为仿生催化剂,通过紫外光谱法、荧光光谱法和凝胶电泳法研究了M-CYC配合物与DNA的相互作用. 结果表明,M-CYC与小牛胸腺DNA(CT DNA)以嵌插方式相互作用,在pH = 8.16的缓冲体系中,其结合常数Kb = 2.0×104 L/mol. 凝胶电泳结果表明,当自由基捕捉剂存在时,M-CYC可将超螺旋pUC19 DNA切割为缺刻型DNA,其切割方式为水解切割. 相似文献
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A new tetrametallic supramolecular complex, [{(bpy)2Ru(dpp)}2Ru(dpp)PtCl2](PF6)6 (bpy = 2,2'-bipyridine, dpp = 2,3-bis(2-pyridyl)pyrazine), has been prepared and characterized. This supramolecular assembly is multifunctional, forming coordinate covalent bonds to DNA through its cis-PtCl2 moiety and photocleaving DNA through its Ru polypyridine chromophores. Electronic absorption spectroscopy shows ligand-based pi-->pi* transitions in the UV with Ru-based metal-to-ligand charge transfer transitions throughout much of the visible. The Ru-->dpp CT transitions center at 542 nm (eta = 35 000 M-1 cm-1). This complex has a HOMO localized on peripheral Ru with E(1/2)oxd = 1.58 V vs Ag/AgCl, and a LUMO based on the mu-dpp connecting Ru and Pt, E(1/2)red = -0.40 V. Gel electrophoresis analysis shows the tetrametallic coordinates to pUC18 DNA and, when excited with visible light, cleaves DNA through an oxygen-mediated pathway. 相似文献
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《Journal of Coordination Chemistry》2012,65(9):1629-1644
Co(II), Ni(II), Cu(II), Zn(II), and VO(IV) complexes containing a versatile β-diketone Schiff-base ligand (obtained by the condensation of 3-furan-2-ylmethylene-2,4-dione and 2-aminophenol) have been synthesized and characterized. Microanalytical, magnetic, and spectroscopic data reveal that the central metal is coordinated to two oxygens of phenolate and two nitrogens of imine of the ligand. Binding of synthesized complexes with calf thymus DNA has been investigated by spectroscopic and electrochemical methods and viscosity measurements. The complexes are able to form adducts with DNA and to distort the double helix by changing the base stacking. Electrostatic binding of vanadyl complex is observed from the weak hypochromism in electronic absorption spectra and no change in the viscosity with DNA. Oxidative DNA cleavage activities of the complexes are studied with supercoiled pUC19 DNA using gel electrophoresis. The hydroxyl radical (OH?) is likely to be the species responsible for the cleavage of pUC19 DNA by the synthesized complexes. Under our experimental conditions, the vanadyl complex has no significant cleavage of DNA. The compounds have been screened for activity against several bacterial and fungal strains and the results are compared with the activity of standard drugs. 相似文献
10.
Purkayastha S Milligan JR Bernhard WA 《The journal of physical chemistry. B》2005,109(35):16967-16973
The purpose of this study was to determine how free radical formation (fr) correlates with single strand break (ssb) and double strand break (dsb) formation in DNA exposed to the direct effects of ionizing radiation. Chemical yields have been determined of (i) total radicals trapped on DNA at 4 K, G(Sigmafr), (ii) radicals trapped on the DNA sugar, Gsugar(fr), (iii) prompt single strand breaks, Gprompt(ssb), (iv) total single strand breaks, Gtotal(ssb), and (v) double strand breaks, G(dsb). These measurements make it possible, for the first time, to quantitatively test the premise that free radicals are the primary precursors to strand breaks. G(fr) were measured by EPR applied to films of pEC (10,810 bp) and pUC18 (2686 bp) plasmids hydrated to Gamma = 22 mol of water/nucleotide and X-irradiated at 4 K. Using these same samples warmed to room temperature, strand breaks were measured by gel electrophoresis. The respective values for pEC and pUC18 were G(fr) = 0.71 +/- 0.02 and 0.61 +/- 0.01 micromol/J, Gtotal(ssb) = 0.09 +/- 0.01 and 0.14 +/- 0.01 micromol/J, G(dsb) = 0.010 +/- 0.001 and 0.006 +/- 0.001 micromol/J, and Gtota)(ssb)/G(dsb) approximately 9 and approximately 20. Surprisingly, Gsugar(fr) approximately 0.06 mumol/J for pUC18 films, less than half of Gtotal(ssb). This indicates that a significant fraction of strand breaks are derived from precursors other than trapped DNA radicals. To explain this disparity, various mechanisms were considered, including one that entails two one-electron oxidations of a single deoxyribose carbon. 相似文献
11.
Synthesis, DNA-binding, and Photocleavage of 2,3-Di-2-pyridylquinoxaline-silver(Ⅰ) Complex 总被引:1,自引:0,他引:1
A new dinuclear complex, [Ag(L)(CH3CN)]2(C1O4)2·2H2O(L=2,3-di-2-pyridylquinoxaline), was prepared and characterized by elemental analyses,IR spectroscopy, and single-crystal X-ray diffraction analyses. The interaction of the complex with calf thymus DNA(CT-DNA) was investigated by absorption, fluorescence spectroscopies, and viscosity measurement. The results suggested that the complex was bound to DNA via an intercalative mode. The intrinsic binding constant value Kb was found to be approximately 1.48×103 L·mol-1. Moreover, the Ag(Ⅰ) complex could cleave the plasmid pUC19 DNA from the supercoiled Form I to the nicked Form Ⅱ under irradiation at 365 nm. 相似文献
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Natarajan Raman Ramaraj Jeyamurugan Mariyyappan Subbulakshmi Raja Boominathan Chithu Ramakrishnan Yuvarajan 《Chemical Papers》2010,64(3):318-328
A novel series of Co(II), Ni(II), Cu(II), Zn(II), and VO(IV) complexes has been synthesized from the Schiff base derived from
4-[(3,4-dimethoxybenzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one and 1,2-diaminobenzene. Structural features
were determined by analytical and spectral techniques. Binding of synthesized complexes with calf thymus DNA (CT DNA) was
studied by spectroscopic methods and viscosity measurements. Experimental results indicate that the complexes are able to
form adducts with DNA and to distort the double helix by changing the base stacking. Lower DNA affinity of the VO(IV) complex
is caused by the change of coordination geometry by the vanadyl ion resulting in a somewhat unfavorable configuration for
the DNA binding. Oxidative DNA cleavage activities of the complexes were studied with supercoiled (SC) pUC19 DNA using gel
electrophoresis; the mechanism studies revealed that the hydroxyl radical is likely to be the reactive species responsible
for the cleavage of pUC19 DNA by the synthesized complexes. The in vitro antimicrobial screening effects of the investigated
compounds were monitored by the disc diffusion method. The synthesized Schiff base complexes exhibit higher antimicrobial
activity than the respective free Schiff base. 相似文献
13.
《应用有机金属化学》2017,31(10)
A novel tetradentate dianionic Schiff base ligand, N ,N ′‐bis(2‐carboxyphenylimine)‐2,5‐thiophenedicarboxaldhyde (H2L) and some first row d‐transition metal chelates (Co(II), Cu(II), Ni(II) and Zn(II)) were synthesized and characterized using various physicochemical and spectroscopic methods. The spectroscopic data suggested that the parent Schiff base ligand coordinates through both deprotonated carboxylic oxygen and imine nitrogen atoms. The free Schiff base and its metal chelates were screened for their antimicrobial activities for various pathogenic bacteria and fungi using the agar well diffusion method. The antibacterial and antifungal activities of all the newly synthesized compounds are significant compared to the standard drugs ciprofloxacin and nystatin. The antioxidant activities of the compounds were determined by reduction of 1,1‐diphenyl‐2‐picrylhydrazyl and compared with that of vitamin C as a standard. DNA binding ability of the novel Schiff base and its complexes was investigated using absorption spectroscopy, fluorescence spectroscopy, viscosity measurements and thermal denaturation. The obtained results clearly demonstrate that the binding affinity with calf thymus DNA follows the order: Cu(II) complex > Ni(II) complex > Zn(II) complex > Co(II) complex >H2L. Furthermore, the DNA cleavage activity of the newly synthesized ligand and its metal complexes was investigated using supercoiled plasmid DNA (pUC18) gel electrophoresis. 相似文献
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UV Light-induced Crosslinking of the Complementary Strands of Plasmid pUC19 DNA Restriction Fragments 总被引:1,自引:0,他引:1
Restriction fragments of pUC19 DNA were irradiated by various doses of UV light and analyzed by denaturing (alkaline) agarose gel electrophoresis. The irradiation generated retarded species whose mobility indicated two crosslinked DNA strands. Quantitative analysis of the experimental data provided an empirical equation relating the fraction of crosslinked DNA molecules to their length and to the dose of their irradiation by UV light. This equation can be used to predict the crosslinking behavior of pUC19-like DNA molecules whose primary structures do not much differ from a random nucleotide sequence. The amount of interstrand crosslinks increased with the (A+T) content of the pUC19 DNA fragments but the dependence was not clear-cut to indicate that oligonucleotide composition of DNA played a significant role as well. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(10):1805-1820
Thiazolidine-4-carboxylic acid derivative (L) derived by condensation of D-penicillamine and 3-methoxy salicylaldehyde was used in synthesis of a copper complex (CuL). The ligand and Cu(II) complex were characterized by elemental analysis and spectral techniques. The DNA binding properties of L and CuL with calf thymus DNA were investigated by various techniques. The ability of compounds to break pUC19 DNA was checked by gel electrophoresis. The radical-scavenging activity was studied using 2,2-diphenyl-1-picrylhydrazyl assay. The ligand and CuL exert cytotoxicity against HCT116 cell line. The compounds were screened for antimicrobial activity against several microorganisms. The effect of the CuL on the surface of penicillium was analyzed by scanning electron microscopy. 相似文献
16.
Ternary Schiff base copper(II) complex [CuL(phen)](ClO(4)), where HL is 2-(methylthio)ethylsalicylaldimine and phen is 1,10-phenanthroline, has been prepared and structurally characterized by X-ray crystallography. The complex shows a CuN(3)OS coordination in a square-pyramidal (4 + 1) geometry with the sulfur as an equatorial ligand. The complex is an avid binder to double-stranded DNA in the minor groove and exhibits both photonuclease and chemical nuclease activity. When exposed to UV light of 312 nm (96 W) or visible light of 532 nm (125 W) under aerobic conditions, the complex causes significant cleavage of supercoiled pUC19 DNA in the absence of any externally added reducing agent or H(2)O(2). 相似文献
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Patra AK Dhar S Nethaji M Chakravarty AR 《Chemical communications (Cambridge, England)》2003,(13):1562-1563
Ternary copper(II) complex, structurally characterized as [Cu(phen)(met)(MeOH)](ClO4) (1) by X-ray crystallography, has 1,10-phenanthroline (phen) as an intercalator/binder to supercoiled pUC19 DNA and L-methionine (met) as a photosensitizer, and the complex displays efficient photonuclease activity on irradiation with UV (312 nm) or visible (436, 532 nm) light through a mechanistic pathway involving singlet oxygen. 相似文献
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Jing Li Yang Yue Ji Zhang Qiao-Sen Lu Kun Li Yu Huang Zhong-Wei Zhang Hong-Hui Lin Na Wang Xiao-Qi Yu 《Transition Metal Chemistry》2008,33(6):759-765
Novel cyclen copper(II) complexes appending different side arms were synthesized as DNA cleavage agents. Both the intermediates
and mononuclear complexes were characterized by 1H NMR, ESI-HRMS, Elemental analyses and IR, and their catalytic activities for DNA cleavage and DNA binding abilities were
investigated. The results indicate that the copper(II) complexes could catalyze the cleavage of supercoiled DNA (pUC 19 plasmid
DNA) under physiological conditions to produce nicked DNA with high yields (nearly 100%) via an oxidative mechanism in the
absence of exogenous agents; The copper complex bearing an 9-anthryl group gave superior DNA interactions to those bearing
phenyl or methyl groups. 相似文献
19.
Dhar S Senapati D Reddy PA Das PK Chakravarty AR 《Chemical communications (Cambridge, England)》2003,(19):2452-2453
Complete cleavage of double stranded pUC19 DNA by the complex [Cu(dpq)2(H2O)](ClO4)2 (dpq, dipyridoquinoxaline) has been observed on irradiation at 694 nm from a pulsed ruby laser, assisted by the metal d-band transition as well as the quinoxaline triplet states in the absence of any external additives. 相似文献
20.
A new dinuclear complex, [Ag(L)(CH3CN)]2(ClO4)2·2H2O(L=2,3-di-2-pyridylquinoxaline), was prepared and characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction analyses. The interaction of the complex with calf thymus DNA(CT-DNA) was investigated by absorption, fluorescence spectroscopies, and viscosity measurement. The results suggested that the complex was bound to DNA via an intercalative mode. The intrinsic binding constant value Kb was found to be approximately 1.48×10^3 L·mol^-1. Moreover, the Ag(I) complex could cleave the plasmid pUC19 DNA from the supercoiled Form Ⅰto the nicked FormⅡ under irradiation at 365 nm. 相似文献