共查询到20条相似文献,搜索用时 15 毫秒
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Valentina Iannace Dr. Ferran Sabaté Molly Bartlett Dr. Jessica Berrones Reyes Dr. Ariadna Lázaro Alessia Fantoni Prof. Ramon Vilar Prof. Laura Rodríguez Prof. Antonella Dalla Cort 《欧洲无机化学杂志》2023,26(28):e202300144
Three series of metal salophen complexes derived from Zn2+, Cu2+, Pt2+ and Ni2+ have been synthesized and their interaction with quadruplex DNA has been evaluated. The compounds differ on the number of ethyl piperidine substituents. They have been characterized by 1H NMR, IR and UV-visible spectroscopies and by HR-mass spectrometry. Their luminescent properties have been also evaluated and we can observe that, as expected, Zn2+ and Pt2+ complexes are those displaying more interesting luminescence with an emission band red-shifted with respect to the corresponding uncoordinated ligand. DNA interactions with G4 and duplex DNA were evaluated by FRET melting assays (for the Zn2+, Cu2+ and Ni2+ complexes) and by emission titrations (for one Pt2+ complex) which indicated that the disubstituted compounds 2-Ni and 2-Pt are the only ones that display good affinity for G4 DNA structures. 相似文献
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Knobloch B Sigel H Okruszek A Sigel RK 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(6):1804-1814
The interaction between divalent metal ions and nucleic acids is well known, yet knowledge about the strength of binding of labile metal ions at the various sites is very scarce. We have therefore studied the stabilities of complexes formed between the nucleic acid model d(pGpG) and the essential metal ions Mg2+ and Zn2+ as well as with the generally toxic ions Cd2+ and Pb2+ by potentiometric pH titrations; all four ions are of relevance in ribozyme chemistry. A comparison of the present results with earlier data obtained for M(pUpU)- complexes allows the conclusion that phosphate-bound Mg2+ and Cd2+ form macrochelates by interaction with N7, whereas the also phosphate-coordinated Pb2+ forms a 10-membered chelate with the neighboring phosphate diester bridge. Zn2+ forms both types of chelates with formation degrees of about 91% and 2.4% for Zn[d(pGpG)]cl/N7 and Zn[d(pGpG)]-cl/PO, respectively; the open form with Zn2+ bound only to the terminal phosphate group, Zn[d(pGpG)]-op, amounts to about 6.8 %. The various intramolecular equilibria have also been quantified for the other metal ions. Zn2+, Cu2+, and Cd2+ also form macrochelates in the monoprotonated M[H;d(pGpG)] species (the proton being at the terminal phosphate group), that is, the metal ion at N7 interacts to some extent with the P(O)2(OH)- group. Thus, this study demonstrates that the coordinating properties of the various metal ions toward a pGpG unit in a nucleic acid differ: Mg2+, Zn2+, and Cd2+ have a significant tendency to bridge the distance between N7 and the phosphate group of a (d)GMP unit, although to various extents, whereas Pb2+ (and possibly Ca2+) prefer a pure phosphate coordination. 相似文献
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Fomina I. G. Sidorov A. A. Aleksandrov G. G. Zhilov V. I. Ikorskii V. N. Novotortsev V. M. Eremenko I. L. Moiseev I. I. 《Russian Chemical Bulletin》2004,53(1):118-126
The reaction of the dinuclear complex Co2(-OOCCMe3)2(2-OOCCMe3)2bpy2 (1) with the polymer [Co(OH)
n
(OOCCMe3)2–n
]
x
afforded the unsymmetrical dinuclear complex bpyCo2(2-O,2-OOCCMe3)(2-O,O"-OOCCMe3)2(2-OOCCMe3) (2). The reaction of 2,2"-dipyridylamine with [Co(OH)
n
(OOCCMe3)2–n
]
x
gave rise to the analogous complex [(C5H4N)2NH]Co2(2-O,2-OOCCMe3)(-OOCCMe3)2(2-OOCCMe3) (3). The reaction of complex 1 with Ni4(3-OH)2(-OOCCMe3)4(OOCCMe3)2(MeCN)2[2-o-C6H4(NH2)(NHPh)]2 (4) produced an isostructural heterometallic analog of complex 2 with composition bpyM2(2-O,2-OOCCMe3)(2-O,O"-OOCCMe3)2(2-OOCCMe3) (5) (M = Co, Ni; Co : Ni = 1 : 1) and the dinuclear heterometallic complex bpy(HOOCCMe3)M(-OH2)(-OOCCMe3)2M(OOCCMe3)2[o-C6H4(NH2)(NHPh)] (6) (M = Co, Ni; Co : Ni = 0.15 : 1.85). Compounds 2 and 5 exhibit ferromagnetic spin-spin exchange interactions. 相似文献
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A series of nickel(II) complexes having the (Me-Tp)2PMA ligand ((Me-Tp)2PMA = bis(5-methyl-2-thiophenemethyl)(2-pyridylmethyl)amine) with nitrates (1), chlorides (2), and perchlorates (3) as anions were synthesized and isolated. All these complexes were successfully characterized by physicochemical methods including X-ray crystallographic analysis. In complex 1, the ligand binds in a bidentate N2 fashion, whereas in the cases of 2 and 3 the ligand binds in the tridentate N2S form. The coordination geometry around the nickel(II) atoms in these complexes is distorted octahedral. 相似文献
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Ronald Lindner Goran N. Kaluđerović Reinhard Paschke Christoph Wagner Dirk Steinborn 《Polyhedron》2008
Reactions of [PtMe3(OCMe2)3](BF4) and [(PtMe3I)4] with pyrazole (pzH) afforded mononuclear pyrazole platinum(IV) complexes [PtMe3(pzH)3](BF4) (1) and [PtMe3I(pzH)2] (2), respectively. The formation of dinuclear pyrazolato bridged platinum(IV) complexes (PPN)[(PtMe3)2(μ-pz)3] (3), (PPN)[(PtMe3)2(μ-I)(μ-pz)2] · 1/2Et2O (4) and [K(18C6)][(PtMe3)2(μ-I)(μ-pz)2] (5) was achieved by the reaction of each 1 and 2 with [PtMe3(OCMe2)3](BF4) in the presence of KOAc followed by reaction with (PPN)Cl (PPN+ = bis(triphenylphosphine)iminium cation) and 18C6, respectively. The reaction of complex 4 with AgO2CCF3 followed by addition of RSR′ (R/R′ = Me/Me, Me/Ph) resulted in the formation of complexes [(PtMe3)2(μ-pz)2(μ-RSR′)] (R/R′ = Me/Me, 6; Me/Ph, 7). All complexes were characterized unambiguously by microanalysis and NMR (1H, 13C) spectroscopic investigations. Additionally, crystal structures of complexes 3 and 4 as well as DFT calculation are presented. Furthermore, in vitro studies on the anti-proliferative activity of complexes 2 and 5 were carried out. 相似文献
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Hunter TM McNae IW Simpson DP Smith AM Moggach S White F Walkinshaw MD Parsons S Sadler PJ 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(1):40-50
Nickel(II)-xylylbicyclam is a potent anti-HIV agent and binds strongly to the CXCR4 co-receptor. We have investigated configurational equilibria of Ni(II)-cyclam derivatives, since these are important for receptor recognition. Crystallographic studies show that both trans and cis configurations are readily formed: [Ni(cyclam)(OAc)(2)] x H(2)O adopts the trans-III configuration with axial monodentate acetates, as does [Ni(benzylcyclam)(NO(3))(2)] with axial nitrate ligands, whereas [Ni(benzylcyclam)(OAc)](OAc)2 x H(2)O has an unusual folded cis-V configuration with Ni(II) coordination to bidentate acetate. UV/Vis and NMR studies show that the octahedral trans-III configuration slowly converts to square-planar trans-I in aqueous solution. For Ni(II)-xylylbicyclam, a mixture of cis-V and trans-I configurations was detected in solution. X-ray diffraction studies showed that crystals of lysozyme soaked in Ni(II)-cyclam or Ni(II) (2)-xylylbicyclam contain two major binding sites, one involving Ni(II) coordination to Asp101 and hydrophobic interactions between the cyclam ring and Trp62 and Trp63, and the second hydrophobic interactions with Trp123. For Ni(II)-cyclam bound to Asp101, the cis-V configuration predominates. 相似文献
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Roth A Buchholz A Rudolph M Schütze E Kothe E Plass W 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(5):1571-1583
A series of bimetallic zinc(II) and nickel(II) complexes based on the novel dinucleating unsymmetric double-Schiff-base ligand benzoic acid [1-(3-{[2-(bispyridin-2-ylmethylamino)ethylimino]methyl}-2-hydroxy-5-methylphenyl)methylidene]hydrazide (H(2)bpampbh) has been synthesized and structurally characterized. The metal centers reside in two entirely different binding pockets provided by the ligand H(2)bpampbh, a planar tridentate [ONO] and a pentadentate [ON(4)] compartment. The utilized ligand H(2)bpampbh has been synthesized by condensation of the single-Schiff-base proligand Hbpahmb with benzoic acid hydrazide. The reaction of H(2)bpampbh with two equivalents of either zinc(II) or nickel(II) acetate yields the homobimetallic complexes [Zn(2)(bpampbh)(mu,eta(1)-OAc)(eta(1)-OAc)] (ZnZn) and [Ni(2)(bpampbh)(mu-H(2)O)(eta(1)-OAc)(H(2)O)](OAc) (NiNi), respectively. Simultaneous presence of one equivalent zinc(II) and one equivalent nickel(II) acetate results in the directed formation of the heterobimetallic complex [NiZn(bpampbh)(mu,eta(1)-OAc)(eta(1)-OAc)] (NiZn) with a selective binding of the nickel ions in the pentadentate ligand compartment. In addition, two homobimetallic azide-bridged complexes [Ni(2)(bpampbh)(mu,eta(1)-N(3))]ClO(4) (NiNi(N(3))) and [Ni(2)(bpampbh)(mu,eta(1)-N(3))(MeOH)(2)](ClO(4))(0.5)(N(3))(0.5) (NiNi(N(3))(MeOH)(2)) were synthesized. In all complexes, the metal ions residing in the pentadentate compartment adopt a distorted octahedral coordination geometry, whereas the metal centers placed in the tridentate compartment vary in coordination number and geometry from square-planar (NiNi(N(3))) and square-pyramidal (ZnZn and NiZn), to octahedral (NiNi and NiNi(N(3))(MeOH)(2)). In the case of complex NiNi(N(3)) this leads to a mixed-spin homodinuclear nickel(II) complex. All compounds have been characterized by means of mass spectrometry as well as IR and UV/Vis spectroscopies. Magnetic susceptibility measurements show significant zero-field splitting for the nickel-containing complexes (D=2.9 for NiZn, 2.2 for NiNi(N(3)), and 0.8 cm(-1) for NiNi) and additionally a weak antiferromagnetic coupling (J=-1.4 cm(-1)) in case of NiNi. Electrochemical measurements and photometric titrations reveal a strong Lewis acidity of the metal center placed in the tridentate binding compartment towards external donor molecules. A significant superoxide dismutase reactivity against superoxide radicals was found for complex NiNi. 相似文献
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Ladislav Habala Ferdinand Devínsky Alexander E. Egger 《Journal of Coordination Chemistry》2018,71(7):907-940
Urease plays a significant role in the pathogenesis of several diseases and also has practical implications in other fields, such as agriculture or chemical analysis. Among the multitude of chemical species known to inhibit urease, metal complexes stand out as a special category due to their specific mechanism of action, distinct from purely organic substances. Their inhibitory activity seems to depend on the type of metal and its oxidation state as well as on the coordination environment of the central atom. Furthermore, the study of the interaction between metal ions and their complexes with urease renders valuable insights into detailed catalytic mechanisms of this enzyme. This brief survey attempts to provide an overview of the published research on urease inhibition by metal complexes. 相似文献
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S. Arounaguiri D. Easwaramoorthy A. Ashokkumar Aparna Dattagupta Bhaskar G. Maiya 《Journal of Chemical Sciences》2000,112(1):1-17
DNA binding and photocleavage characteristics of a series of mixed-ligand complexes of the type [M(phen)2LL]n+ (where M = Co(III), Ni(II) or Ru(II), LL = 1,10-phenanthroline (phen), phenanthroline-dione (phen-dione) or dipyridophenazine
(dppz) andn = 3 or 2) have been investigated in detail. Various physico-chemical and biochemical techniques including UV/Visible, fluorescence
and viscometric titration, thermal denaturation, and differential pulse voltammetry have been employed to probe the details
of DNA binding by these complexes; intrinsic binding constants (K
b) have been estimated under a similar set of experimental conditions. Analysis of the results suggests that intercalative
ability of the coordinated ligands varies as dppz>phen>phen-dione in this series of complexes. While the Co(II) and Ru(II)
complexes investigated in this study effect photocleavage of the supercoiled pBR 322 DNA, the corresponding Ni(II) complexes
are found to be inactive under similar experimental conditions. Results of detailed investigations carried out inquiring into
the mechanistic aspects of DNA photocleavage by [Co(phen)2(dppz)]3+ have also been reported. 相似文献
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Dr. Yusuke Takezawa Shiori Sakakibara Prof. Dr. Mitsuhiko Shionoya 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(67):16626-16633
DNA three-way junction (3WJ) structures are essential building blocks for the construction of DNA nanoarchitectures. We have synthesized a bipyridine (bpy)-modified DNA 3WJ by using a newly designed bpy-modified nucleoside, Ubpy- 3 , in which a bpy ligand is tethered via a stable amide linker. The thermal stability of the bpy-modified 3WJ was greatly enhanced by the formation of an interstrand NiII(bpy)3 complex at the junction core (ΔTm=+17.7 °C). Although the stereochemistry of the modification site differs from that of the previously reported bpy-modified nucleoside Ubpy- 2 , the degree of the NiII-mediated stabilization observed with Ubpy- 3 was comparable to that of Ubpy- 2 . Structure induction of the 3WJs and the duplexes was carried out by the addition or removal of NiII ions. Furthermore, NiII-mediated self-sorting of 3WJs was performed by using the bpy-modified strands and their unmodified counterparts. Both transformations were driven by the formation of NiII(bpy)3 complexes. The structural induction and self-sorting of bpy-modified 3WJs are expected to have many potential applications in the development of metal-responsive DNA materials. 相似文献
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Zh. V. Dobrokhotova I. G. Fomina M. A. Kiskin A. A. Sidorov V. M. Novotortsev I. L. Eremenko 《Russian Chemical Bulletin》2006,55(2):256-266
Solid-phase thermal decomposition of polynuclear NiII and CoII pivalate complexes was studied by differential scanning calorimetry and thermogravimetry. The decomposition of the polynuclear
(from bi-to hexanuclear) CoII carboxylate complexes is accompanied by aggregation to form a volatile octanuclear complex. Thermolysis of the polynuclear
NiII carboxylates results in their destructure, and the phase composition of the decomposition products is determined by the
nature of coordinated ligands.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 250—260, February, 2006. 相似文献
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Tamilselvi A Nethaji M Mugesh G 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(30):7797-7806
Biomimetic systems containing one or two zinc(II) ions supported by phenolate ligands were developed as functional mimics of metallo-beta-lactamase. These complexes were shown to catalytically hydrolyze beta-lactam substrates, such as oxacillin and penicillin G. The dinuclear zinc complex 1, which has a coordinated water molecule, exhibits high beta-lactamase activity, whereas the dinuclear zinc complex 2, which has no water molecules, but labile chloride ligands, shows a much lower activity. The high beta-lactamase activity of complex 1 can be ascribed to the presence of a zinc-bound water molecule that is activated by being hydrogen bonded to acetate substituents. The kinetics of the hydrolysis of oxacillin by complex 1 and the effect of pH on the reaction rates are reported in detail. In addition, the kinetic parameters obtained for the synthetic analogues are compared with those of the natural metallo-beta-lactamase from Bacillus cereus (BcII). To understand the role of the second metal ion in hydrolysis, the syntheses and catalytic activities of two mononuclear complexes (3 and 4) that include coordinated water molecules are described. Interestingly, the mononuclear zinc complexes 3 and 4 also exhibit high activity, supporting the assumption that the second zinc ion is not crucial for the beta-lactamase activity. 相似文献
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Zhang J Thomas DS Berners-Price SJ Farrell N 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(21):6391-6405
Reported herein is a detailed study of the kinetics and mechanism of formation of a 1,4-GG interstrand cross-link by the dinuclear platinum anticancer compound [15N][{cis-PtCl(NH3)2}2{mu-NH2(CH2)6NH2}]2+ (1,1/c,c (1)). The reaction of [15N]1 with 5'-{d(ATATGTACATAT)2} (I) has been studied by [1H,15N] HSQC NMR spectroscopy in the presence of different concentrations of phosphate. In contrast with the geometric trans isomer (1,1/t,t), there was no evidence for an electrostatic preassociation of 1,1/c,c with the polyanionic DNA surface, and the pseudo-first-order rate constant for the aquation of [(15)N]1 was actually slightly higher (rather than lower) than that in the absence of DNA. When phosphate is absent, the overall rate of formation of the cross-link is quite similar for the two geometric isomers, occurring slightly faster for 1,1/t,t. A major difference in the DNA binding pathways is the observation of phosphate-bound intermediates only in the case of 1,1/c,c. 15 mM phosphate causes a dramatic slowing in the overall rate of formation of DNA interstrand cross-links due to both the slow formation and slow closure of the phosphate-bound monofunctional adduct. A comparison of the molecular models of the bifunctional adducts of the two isomers shows that helical distortion is minimal and globally the structures of the 1,4 interstrand cross-links are quite similar. The effect of carrier ligand was investigated by similar studies of the ethylenediamine derivative [15N]1-en. A pKa value of 5.43 was determined for the [15N]1,1/c,c-en diaquated species. The rate of reaction of [15N]1-en with duplex I is similar to that of 1,1/c,c and the overall conformation of the final adduct appears to be similar. The significance of these results to the development of "second-generation" polynuclear platinum clinical candidates based on the 1,1/c,c chelate (dach) series is discussed. 相似文献
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The mononuclear cations of the general formula [(η6-arene)RuCl(dpqMe2)]+ (dpqMe2 = 6,7-dimethyl-2,3-di(pyridine-2-yl)quinoxaline; arene = C6H6, 1; C6H5Me, 2; p-PriC6H4Me, 3; C6Me6, 4) as well as the dinuclear dications [(η6-arene)2Ru2Cl2(μ-dpqMe2)]2+ (arene = C6H6, 5; C6H5Me, 6; p-PriC6H4Me, 7; C6Me6, 8) have been synthesised from 6,7-dimethyl-2,3-di(pyridine-2-yl)quinoxaline (dpqMe2) and the corresponding chloro complexes [(η6-C6H6)Ru(μ-Cl)Cl]2, [(η6-C6H5Me)Ru(μ-Cl)Cl]2, [(η6-p-PriC6H4Me)Ru(μ-Cl)Cl]2 and [(η6-C6Me6)Ru(μ-Cl)Cl]2, respectively. The X-ray crystal structure analyses of [1][PF6], [3][PF6] and [6][PF6]2 reveal a typical piano-stool geometry around the metal centre; in the dinuclear complexes the two chloro ligands, with respect to each other, are found to be trans oriented. 相似文献
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Padavattan Govindaswamy Bruno Therrien Petr Štěpni?ka Ji?í Ludvík 《Journal of organometallic chemistry》2007,692(17):3664-3675
The mononuclear cations [(η5-C5Me5)RhCl(bpym)]+ (1), [(η5-C5Me5)IrCl(bpym)]+ (2), [(η6-p-PriC6H4Me)RuCl(bpym)]+ (3) and [(η6-C6Me6)RuCl(bpym)]+ (4) as well as the dinuclear dications [{(η5-C5Me5)RhCl}2(bpym)]2+ (5), [{(η5-C5Me5)IrCl}2(bpym)]2+ (6), [{(η6-p-PriC6H4Me)RuCl}2(bpym)]2+ (7) and [{(η6-C6Me6)RuCl}2(bpym)]2+ (8) have been synthesised from 2,2′-bipyrimidine (bpym) and the corresponding chloro complexes [(η5-C5Me5)RhCl2]2, [(η5-C5Me5)IrCl2]2, [(η6-PriC6H4Me)RuCl2]2 and [(η6-C6Me6)RuCl2]2, respectively. The X-ray crystal structure analyses of [3][PF6], [5][PF6]2, [6][CF3SO3]2 and [7][PF6]2 reveal a typical piano-stool geometry around the metal centres; in the dinuclear complexes the chloro ligands attached to the two metal centres are found to be, with respect to each other, cis oriented for 5 and 6 but trans for 7. The electrochemical behaviour of 1-8 has been studied by voltammetric methods. In addition, the catalytic potential of 1-8 for transfer hydrogenation reactions in aqueous solution has been evaluated: All complexes catalyse the reaction of acetophenone with formic acid to give phenylethanol and carbon dioxide. For both the mononuclear and dinuclear series the best results were obtained (50 °C, pH 4) with rhodium complexes, giving turnover frequencies of 10.5 h−1 for 1 and 19 h−1 for 5. 相似文献