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1.
This work reports the synthesis, characterization, and aqueous chemistry of a series of cytotoxic [Au(polypyridyl)Cl2]PF6 complexes {(where polypyridyl = dipyrido[3,2-f:2′,3′-h] quinoxaline (DPQ), dipyrido[3,2-a:2′,3′-c] phenazine (DPPZ) and dipyrido[3,2-a:2′,3′-c](6,7,8,9-tetrahydro) phenazine (DPQC))}. The crystal structure of [Au(DPQ)Cl2]PF6 was determined as example of the series and exhibits the anticipated square planar geometry common for d8 coordination complexes. The crystals of the complex belong to the space group P21/n with a = 7.624(2) Å, b = 18.274(5) Å, c = 14.411(14) Å, β = 98.03(3)°, and Z = 4. In 1H NMR studies of these compounds in the presence of aqueous buffer, all four complexes rapidly converted to the dihydroxy species [Au(polypyridyl)(OH)2] in a stepwise fashion. However, the [Au(polypyridyl)]3+ fragment believed to impart cytotoxicity in human ovarian cancer cell lines (A2780) remained intact and appeared stable for days. It was also noted that these Au(III) complexes were readily reduced in the presence of the common biological reducing agents, reduced glutathione and sodium ascorbate. How solution and redox stability may affect the biological activity of these novel Au(III) complexes is discussed.  相似文献   

2.
By reaction of Tl(C6Cl5)2Cl with Au(C6Cl5)(tht) (tht = tetrahydrothiophen) or [N(PPh3)2] [Au(C6- Cl5)Cl] the gold(III) complexes [Au(C6Cl5)3(tht)] or [N(PPh3)2][Au(C6Cl5)3Cl] respectively, can be prepared. They are the first tris(pentachlorophenyl)- gold(III) complexes to be reported. The ready displacement of tht by other neutral or anionic ligands leads to the synthesis of Au(C6Cl5)3(Ph2PCH2PPh2) or Q[Au(C6Cl5)3X] (Q=N(PPh3)2, PPh3Me or PPh2Me2; X=C6F5, SCN, Br or I).  相似文献   

3.
Four related ruthenium(III) complexes, with the formula mer-[RuCl3(dmso)(N−N)] (dmso = dimethyl sulfoxide; N−N = 2,2′-bipyridine (1), 1,10-phenantroline (2), dipyrido[3,2-f:2′,3′-h]quinoxaline (3) and dipyrido[3,2-a:2′,3′-c]phenazine (4)), have been reported. Complexes 3 and 4 are newly synthesized and characterized by X-ray diffraction. The hydrolysis process of 1-4 has been studied by UV-vis measurement, and it has been found that the extension of the N−N ligands can increase the stability of the complexes. The binding of these complexes with DNA has been investigated by plasmid cleavage assay, competitive binding with ethidium bromide (EB), DNA melting experiments and viscosity measurements. The DNA binding affinity is increased with the extension of the planar area of the N−N ligands, and complex 4 shows an intercalative mode of interaction with DNA. The in vitro anticancer activities of these compounds are moderate on the five human cancer cell lines screened.  相似文献   

4.
The synthesis, characterization, and application in asymmetric catalytic cyclopropanation of Rh(III) and Ir(III) complexes containing (Sa,RC,RC)-O,O′-[1,1′-binaphthyl-2,2′-diyl]-N,N′-bis[1-phenyl-ethyl]phosphoramidite (1) are reported. The X-ray structures of the half-sandwich complexes [MCl2(C5Me5)(1P)] (M = Rh, 2a; M = Ir, 2b) show that the metal-phosphoramidite bond is significantly shorter in the Ir(III) analog. Chloride abstraction from 2a (with CF3SO3SiMe3 or with CF3SO3Me) and from 2b (with AgSbF6) gives the cationic species [MCl(C5Me5)(1,2-η-1P)]+ (M = Rh, 3a; M = Ir, 3b), which display a secondary interaction between the metal and a dangling phenethyl group (NCH(CH3)Ph) of the phosphoramidite ligand, as indicated by NMR spectroscopic studies. Complexes 3a and 3b slowly decompose in solution. In the case of 3b, the binuclear species [Ir2Cl3(C5Me5)2]+ is slowly formed, as indicated by an X-ray study. Preliminary catalytic tests showed that 3a cyclopropanates styrene with moderate yield (35%) and diastereoselectivity (70:30 trans:cis ratio) and with 32% ee (for the trans isomer).  相似文献   

5.
Two complexes of Au(III) with dimethylglyoxime of compositions [AuIII(HDMG)2][AuIIICl4] (1) and [AuIII(HDMG)2][AuICl2] (2) were synthesized and characterized by X-ray structural analysis. It was shown that in [AuIII(HDMG)2]+ cation Au(III) has a square-planar environment, and the oxygen atoms of oxime groups are joined by intramolecular H-bond. The secondary Au?Au and Au?Cl interactions in the crystal are discussed.  相似文献   

6.
Gold compounds are being investigated as potential antitumor drugs. Some gold(III) derivatives have been shown to induce cell death in solid tumors but their mechanism of action differs from that of cisplatin, since most of these compounds do not bind to DNA. We have explored cellular events triggered by three different iminophosphorane-organogold(III) compounds in leukemia cells (a neutral compound with two chloride ligands [Au{κ2-C,N-C6H4(PPh2 = N(C6H5)-2}Cl2] 1, and two cationic compounds with either a dithiocarbamate ligand [Au{κ2-C,N-C6H4(PPh2 = N(C6H5)-2}(S2CN-Me2)]PF62, or a water-soluble phosphine and a chloride ligand [Au{κ2-C,N-C6H4(PPh2 = N(C6H5)-2}(P{Cp(m-C6H4-SO3Na)2}3) Cl]PF63). All three compounds showed higher toxicity against leukemia cells when compared to normal T-lymphocytes. Compounds 1 and 2 induced both necrosis and apoptosis, while 3 was mainly apoptotic. Necrotic cell death induced by 1 and 2 was Bax/Bak- and caspase-independent, while apoptosis induced by 3 was Bax/Bak-dependent. Reactive oxygen species (ROS) production at the mitochondrial level was a critical step in the antitumor effect of these compounds.  相似文献   

7.
In the last few years gold(III) complexes have attracted growing attention in the medicinal chemistry community as candidate anticancer agents. In particular some organogold(III) compounds manifested quite attractive pharmacological behaviors in preclinical studies. Here we compare the chemical and biological properties of the novel organogold(III) complex [Au(bipydmb?H)(NH(CO)CH3)][PF6] (Aubipyaa) with those of its parent compounds [Au(bipydmb?H)(OH)][PF6] (Aubipyc) and [Au2(bipydmb?H)2)(μ?O)][PF6]2 (Au2bipyc), previously synthesized and characterized. The three study compounds were comparatively assessed for their antiproliferative actions against HCT-116 cancer cells, revealing moderate cytotoxic effects. Proapoptotic and cell cycle effects were also monitored. Afterward, to gain additional mechanistic insight, the three gold compounds were challenged against the model proteins HEWL, RNase A and cytochrome c and reactions investigated through UV–Vis and ESI–MS analysis. A peculiar and roughly invariant protein metalation profile emerges in the three cases consisting of protein binding of {Au(bipydmb?H)} moieties. The implications of these results are discussed in the frame of current knowledge on anticancer gold compounds.  相似文献   

8.
A series of gold(III) metalacycle of five-, six- and seven-membered ring was prepared by reacting Auric acid (HAuCl4 · 3H2O) with 1 equiv. unsubstituted ethylenediamine (en), propylene diamine (pn) and butylenediamine (bn) ligands and with some N-mono-substituted as well as N,N′-disubstituted ethylenediamine ligands. The general formula of these complexes is [Au(alkyldiamine)Cl2]Cl. These complexes are characterized by melting point and elemental analysis, while structural analysis was done by spectroscopic techniques such as UV-Vis, Far-IR, IR spectroscopy, 1H and 13C solution as well as 13C and 15 N solid-state NMR. The solid-state 15 N NMR shows that the chemical shift difference between free and bound ligand decreases as bn > pn > en, indicating stronger Au-N bond for bn complex compared to pn and en. UV-Vis shows relative stability of the Au(III) complexes of unsubstituted ethylenediamine with respect to N,N′-di-substituted ethylenediamine. Far-IR data show the six-membered metalacycle gold(III) alkanediamine complexes to be more stable. Spectroscopic data are evaluated by comparisons with calculated data of the built and optimized structure by gaussian03 at the RB3LYP level with LanL2DZ bases set.  相似文献   

9.
Four cobalt(III) polypyridyl complexes, [Co(phen)3−n(dpq)n]3+ (phen = 1,10-phenanthroline, dpq = dipyrido[3,2-f:2′,3′-h]-quinoxaline) (n = 0, 1, 2, and 3) were synthesized and the influences of the dpq ligand on the photophysical properties, electrochemical properties, DNA binding affinities, as well as photonuclease activities of the complexes, were examined in detail. The presence of dpq ligand increases the DNA binding affinities of the corresponding complexes remarkably with respect to [Co(phen)3]3+. With the sequential substitution of phen ligand by dpq ligand, the 1O2 quantum yields of the corresponding complexes are enhanced greatly. As a result, the photonuclease activities follow the order of [Co(dpq)3]3+ > [Co(phen)(dpq)2]3+ > [Co(phen)2(dpq)]3+ ? [Co(phen)3]3+. It was found all the examined complexes can generate OH upon UV irradiation, and OH is also involved in DNA photocleavage as reactive oxygen species.  相似文献   

10.
A new series of pendant-type polymer-cobalt(III) complexes, [Co(LL)2(BPEI)Cl]2+, (where BPEI?=?branched polyethyleneimine, LL?=?dipyrido[3,2-a:2′,3′-c](6,7,8,9-tetrahydro)phenazine (dpqc), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq) and imidazo[4,5-f]1,10-phenanthroline (ip)) each with three different degrees of coordination have been synthesized and characterized. Studies to know the mode and strength of interaction between these polymer–metal complexes and calf thymus DNA have been performed by UV–Visible absorption and emission techniques. Among these series, each polymer metal complex having higher binding strength with DNA has been selected to test against human cancer/normal cell lines. On the basis of these spectral studies, it is proposed that our polymer–metal complexes bind with DNA mainly through intercalation along with some electrostatic binding. The order of binding strength for the complexes with ligand, dpqc?>?dpq?>?ip. The analysis of the results suggests that polymer–cobalt(III) complexes with higher degree of coordination effectively binds with DNA due to the presence of large number of positively charged cobalt(III) chelates in the polymer chain which cooperatively act to increase the overall binding strength. These polymer–cobalt(III) complexes with hydrophobic ligands around the cobalt(III) metal centre favour the base stacking interactions via intercalation. All the complexes show very good anticancer activities and increasing of binding strength results in higher inhibition value. The polymer–cobalt(III) complex with dpqc ligand possess two fold increased anticancer activity when compared to complexes with other ligands against MCF-7 cells. Besides, the complexes were insensitive towards the growth of normal cells (HEK-293) at the IC50 concentration.  相似文献   

11.
A series of Rh(III) mixed ligand polypyridine type complexes have been prepared. Complexes of the form [Rh(L)2(L)]n+, where n=2/3, L=2,2-bipyridine (bpy)/1,10-phenanthroline (phen) and L=3-(pyridin-2-yl)-1,2,4-triazole (Hpytr), 1-methyl-3-(pyridin-2-yl)-1,2,4-triazole (1M3pytr), 4-methyl-3-(pyridin-2-yl)-1,2,4-triazole (4Mpytr), 3,5-bis(pyridin-2-yl)-1,2,4-triazole (Hbpt), 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole (NH2bpt) and 3-(pyridin-2-yl)-5-phenyl-1,2,4-triazole (HPhpytr), have been prepared and their synthesis and characterisation are reported. Crystals of [Rh(bpy)2(Phpytr)](PF6)2 and [Rh(phen)2(NHbpt)](PF6)2 were obtained and their structures determined. Analysis of X-ray crystallographic data showed that coordination of the metal centre in [Rh(phen)2(NHbpt)](PF6)2 occurs via the amine moiety and a nitrogen of the pyridine ring. NMR studies illustrated that coordination to the NH2bpt ligand was also possible via a nitrogen of the triazole ring and the pyridine ring forming the complex [Rh(phen)2(NH2bpt)](PF6)3. The absorption and emission properties of the complexes studied were found to be π-π* in nature and preliminary evidence suggests that all complexes with the exception of [Rh(phen)2(NHbpt)](PF6)2 and [Rh(bpy)2(NHbpt)](PF6)2 are dual emitting at 77 K.  相似文献   

12.
Under 254 nm irradiation in chloroform, [Re2Cl8]2− is converted cleanly to [Re2Cl9]. The reaction is initiated primarily through light absorbed by the chloroform. The experimental rate expression is , where I0 is the incident light intensity and fS is the fraction of light absorbed by the solvent. The rate law is consistent with mechanisms involving either [Re2Cl8] or [Re2Cl9]2− as an intermediate.  相似文献   

13.
A gold(III) complex possessing 5,6-dimethyl-1,10-phenanthroline (5,6DMP) was synthesized and fully characterized using standard spectroscopic techniques, as well as X-ray crystallography and elemental analysis. The complex [(5,6DMP)AuCl2][BF4] (2) was found to possess a distorted square planar geometry about the gold(III) center, commonplace for d8 Au(III) cations possessing sterically un-hindered polypyridyl ligands. Compound 2 was evaluated for its potential use as an anticancer therapeutic. It was determined that the complex is stable in phosphate buffer over a 24-hour period, thought it does undergo rapid reduction in the presence of equimolar amounts of reduced glutathione (GSH) and ascorbic acid. The DNA binding and in vitro tumor cytotoxicity of the title compound 2 were also determined. It was found to undergo weak and reversible binding to calf thymus DNA, and was more cytotoxic towards a panel of human cancer cell lines than the commonly used chemotherapy agent cisplatin. Cytotoxicity experiments with the free 5,6DMP ligand indicate that the ligand has IC50 values that are slightly lower than those observed for the gold complex (2), and coupled with the fact that the ligand appears to be released from the gold(III) metal center in reducing environments, this suggests the ligand itself may play an important role in the antitumor activity of the parent gold complex.  相似文献   

14.
Reported herein are studies of the concentration and temperature dependent interactions with DNA of the stereochemically defined mixed-metal supramolecular complexes, [(tpy)Ru(tppz)PtCl](PF6)3 and [ClPt(tppz)Ru(tppz)PtCl](PF6)4 (tpy = 2,2′:6′,2′′-terpyridine and tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine). These metal complexes couple a ruthenium based light absorber (LA) to the bioactive platinum sites (BAS) using a tridentate bridging ligand (BL). The complexes exhibit intense Ru → tppz(π∗) metal to ligand charge transfer (MLCT) transitions in the visible region and adopt a square planar geometry around the Pt(II) center. The effect of incubating these metal complexes with DNA on the subsequent migration of DNA through an agarose gel was found to be more dramatic than that observed for the well known anticancer drug, cis-[Pt(NH3)2Cl2] (cisplatin). This effect was enhanced with increased incubation temperature. Unwinding of supercoiled plasmid DNA was found to be more pronounced for the trimetallic complex, [ClPt(tppz)Ru(tppz)PtCl](PF6)4, than for the bimetallic complex, [(tpy)Ru(tppz)PtCl](PF6)3.  相似文献   

15.
We have studied the kinetics of the complex formation of gold(III) complexes, [AuCl2(en)]+ (dichlorido(ethylenediamine)aurate(III)-ion) and [AuCl2(SMC)] (dichlorido (S-methyl-l-cysteine)aurate(III)) with four biologically N-donor nucleophiles. It was shown that studied ligands have a high affinity for gold(III) complex, which may have important biological implications, since the interactions of Au(III) with DNA is thought to be responsible for the anti-tumour activity. The [AuCl2(SMC)] complex is more reactive than [AuCl2(en)]+. L-His reacts faster than the other N-donor nucleophiles in the reaction with [AuCl2(en)]+, but in the reaction with [AuCl2(SMC)] 5′-GMP is the best nucleophile. Gold(III) complexes are much more reactive than Pt(II) complexes with the same nucleophiles. The activation parameters for all studied reactions suggest an associative substitution mechanism. The cytotoxicity of gold(III) complexes, [AuCl2(en)]+, [AuCl2(SMC)] and [AuCl2(DMSO)2]+ was evaluated in vitro against chronic lymphocytic leukemia cells, obtained from blood of patients with chronic lymphocytic leukemia (CLL). The [AuCl2(en)]+ complex show comparable cytotoxicity profiles compared to cisplatin.  相似文献   

16.
Hydrophilic, monocationic [M(L)4]PF6 complexes (M = Cu or Ag; L: thp = tris(hydroxymethyl)phosphine, L: PTA = 1,3,5-triaza-7-phosphaadamantane, L: thpp = tris(hydroxypropyl)phosphine) were synthesized by ligand exchange reaction starting from [Cu(CH3CN)4]PF6 or AgPF6 precursors at room temperature in the presence of an excess of the relevant phosphine. The related [Au(L)4]PF6 complexes (L = thp, PTA or thpp) were synthesized by metathesis reactions starting from [Au(L)4]Cl at room temperature in the presence of equimolar quantity of TlPF6. The three series of complexes [M(L)4]PF6 were tested as cytotoxic agents against a panel of several human tumour cell lines also including a defined cisplatin resistant cell line. These investigations have been carried out in comparison with the clinically used metallodrug cisplatin and preliminary structure-activity relationships are presented. The best results in terms of in vitro antitumour activity were achieved with metal-thp species and, among the coinage metal complexes, copper derivatives were found to be the most efficient drugs. Preliminary studies concerning the mechanism of action of these [M(L)4]PF6 species pointed to thioredoxin reductase as one of the putative cellular targets of gold and silver complexes and provided evidence that copper derivatives mediated their cytotoxic effect through proteasome inhibition.  相似文献   

17.
The white homoleptic high-spin iron(II) complexes Fe[TpMe2,4Cl]2 (1) was isolated in quantitative yield from reaction mixtures containing 1 equiv of FeCl2(THF)1.5 and 2 equiv of K[TpMe2,4Cl] (TpMe2,4Cl = hydrotris[(4-chloro-3,5-dimethyl-pyrazolyl)]borate). Its purple low-spin iron(III) counterparts 1[O3SCF3] and 1[PF6] were synthesized and isolated in 85% yields upon treatment of 1 with 1 equiv of silver triflate and silver hexafluorophosphate, respectively. The three paramagnetic compounds are air and thermally stable as solids and in solution; they were characterized by elemental analyses, IR, magnetic susceptibility measurements, 1H NMR, and Mössbauer spectroscopy. In addition, 1[PF6] was authenticated by a single-crystal X-ray diffraction. The two scorpionate ligands are κ3-N,N′,N′′ ligated to the central FeIII ion, forming an almost perfect FeN6 octahedron with an average Fe-N bond distance of 1.9551(18) Å. In addition, complex 1 which oxidizes reversibly at E1/2 = 0.483 V/SCE (ΔEp = 94 mV), remains high-spin (S = 2) when the temperature is lowered to 2 K.  相似文献   

18.
A series of tetramethylammonium tetrahalogenoferrates(III), [FeBr4−nCln] (n = 0, 1, 3, 4), of general formula [(CH3)4N][FeBr4−nCln], have been synthesized. The crystal and molecular structures of [(CH3)4N][FeCl4] were determined. The compound is isostructural with its [FeBr4−nCln] (n = 0, 1, 3, 4) analogues. Magnetic measurements of the powdered samples of [(CH3)4N][FeBr4−nCln] gave negative values of the Weiss constant, which suggest antiferromagnetic coupling. The strength of the antiferromagnetic interactions strongly depends on the kind of halide ligands in the coordination sphere of iron(III) and increases with an increasing number of the bromide anions.  相似文献   

19.
A comparative study of metallophilic interactions of [Pt(tpy)X]+ cations (tpy = 2,2′:6′,2″-terpyridine) in the presence of two different types of anions, (i) [] anions that form double salts and (ii) simple p-block anions, is reported. Single-crystal X-ray diffraction data, solution-state 195Pt NMR spectra, and variable temperature solid-state luminescence spectra are reported. Three [Pt(tpy)Cl]Y derivatives (Y = SbF6, 1, SbF6·CH3CN, 4, PF6, 2) and the [Pt(tpy)Br]PF6 analog, 3, as well as two new double salts [Pt(tpy)CN][Au(CN)2], 5, and [Pt(tpy)CN]2[Au(C6F5)2](PF6), 6, have been synthesized and characterized. Structural analysis shows consistent patterns in Pt···Pt interactions that vary slightly depending on the coordinating halogen or pseudo-halogen X, counter anion Y, and lattice solvent. Metallophilic interactions are seen between [Pt(tpy)X]+ cations with all types of X ligands, but only with π-accepting X′ ligands from [] anions are Pt?Au metallophilic interactions seen to be favored over Pt?Pt interactions. The [Au(CN)2] anion consistently forms Pt···Au metallophilic contacts, unlike [Au(C6F5)2]. The 195Pt NMR chemical shifts are ∼−2750 ppm for π-donor ligands and near −3120 ppm for π-acceptor ligands in [Pt(tpy)X]PF6 compounds. Luminescence data show an unusual blue shift in [Pt(tpy)CCPh][Au(C6F5)2] versus [Pt(tpy)CCPh]PF6 ascribed to an intermolecular charge transfer.  相似文献   

20.
Reaction between Re2(OAc)4Cl2 and N,N′-dicyclohexylbenzamidine (HDCyBA) under molten conditions yielded Re2(DCyBA)2Cl4 (1); reaction of [Bu4N]2[Re2Cl8] with N,N′-di(3-methoxyphenyl)formamidine (HDmAniF) resulted in Re2(DmAniF)2Cl4 (2); reaction of cis-Re2(OAc)2Cl4 with HDmAniF under reflux conditions resulted in cis-Re2(OAc)2(DmAniF)2Cl2 (3). Reaction between Re2(OAc)4Cl2 and α,α,α′,α′-tetramethyl-1,3-benzenedipropionic acid (H2esp) under reflux conditions led to Re2(esp)2Cl2 (4). Crystallographic studies of compounds 1-4 revealed Re-Re bond lengths of 2.1679(6), 2.1804(5), 2.2468(7), and 2.2304(6) Å, respectively, which are consistent with the presence of Re-Re quadruple bond. Also reported are electrochemical properties of compounds 1-4.  相似文献   

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