首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Two 1D organic-inorganic coordination polymers, [Cd(3-pmpmd)(CH3CN)2(H2O)2]n · 2n(ClO4)2 (1) and [Zn(3-pmpmd)1.5(H2O)2]n · 2n(ClO4)2 · nCH3CN (2), were obtained from M(ClO4)2 (M = Cd, Zn) and the semi-flexible 3,3′-N-donor bis-pyridyl ligand 3-pmpmd: 1 has an 1D zigzag framework with 3-pmpmd in the ZT-mode (anti, trans-) conformation, while 2 has an 1D rod and loop network with 3-pmpmd in both ZT- and ZC-mode (anti, cis-) conformations. Results showed that the metal ions could influence the coordination mode of a semi-flexible bis-pyridyl ligand.  相似文献   

2.
Two ruthenium nitrosyl bis-pyridyl/biscarboxamido compounds, [Ru(NO)(bpp)Cl · 2H2O] [bpp = N,N′-bis(2-pyridinecarboxamide)-1,3-propane dianion] and [Ru(NO)(bpe)Cl · 2H2O] [bpe = N,N′-(bis-2-pyridinecarboxamide)-1,2-ethane dianion] have been characterized by 1H NMR, 13C{1H} NMR, and IR spectroscopies, electrospray ionizaton mass spectrometry, and X-ray crystallography.  相似文献   

3.
Statistics-based experimental designs were applied to optimize the culture conditions for tetrahydrofuran (THF) degradation by a newly isolated Rhodococcus sp. YYL that tolerates high THF concentrations. Single factor experiments were undertaken for determining the optimum range of each of four factors (initial pH and concentrations of K2HPO4 · 3H2O, NH4Cl and yeast extract) and these factors were subsequently optimized using the response surface methodology. The Plackett–Burman design was used to identify three trace elements (Mg2+, Zn2+and Fe2+) that significantly increased the THF degradation rate. The optimum conditions were found to be: 1.80 g/L NH4Cl, 0.81 g/L K2HPO4 · 3H2O, 0.06 g/L yeast extract, 0.40 g/L MgSO4 · 7H2O, 0.006 g/L ZnSO4 · 7H2O, 0.024 g/L FeSO4 · 7H2O, and an initial pH of 8.26. Under these optimized conditions, the maximum THF degradation rate increased to 137.60 mg THF h−1 g dry weight in Rhodococcus sp. YYL, which was nearly five times of that by the previously described THF degrading Rhodococcus strain.  相似文献   

4.
Combined pH-metric, UV-Vis, 1H NMR and EPR spectral investigations on the complex formation of M(II) ions (M=Co, Ni, Cu and Zn) with N-(2-benzimidazolyl)methyliminodiacetic acid (H2bzimida, hereafter H2L) in aqueous solution at a fixed ionic strength, I=10−1 mol dm−3, at 25 ± 1 °C indicate the formation of M(L), M(H−1L) and M2(H−1L)+ complexes. Proton-ligand and metal-ligand constants and the complex formation equilibria have been elucidated. Solid complexes, [M(L)(H2O)2] · nH2O (n=1 for M = Co and Zn, n=2 for M = Ni) and {Cu (μ-L) · 4H2O}n, have been isolated and characterized by elemental analysis, spectral, conductance and magnetic measurements and thermal studies. Structures of [Ni(L)(H2O)2] · 2H2O and {Cu(μ-L) · 4H2O}n have been determined by single crystal X-ray diffraction. The nickel(II) complex exists in a distorted octahedral environment in which the metal ion is coordinated by the two carboxylate O atoms, the amino-N atom of the iminodiacetate moiety and the pyridine type N-atom of the benzimidazole moiety. Two aqua O atoms function as fifth and sixth donor atoms. The copper(II) complex is made up of interpenetrating polymeric chains of antiferromagnetically coupled Cu(II) ions linked by carboxylato bridges in syn-anti (apical-equatorial) bonding mode and stabilized via interchain hydrogen bonds and π-π stacking interactions.  相似文献   

5.
In [PtX(PPh3)3]+ complexes (X = F, Cl, Br, I, AcO, NO3, NO2, H, Me) the mutual cis and trans influences of the PPh3 groups can be considered constants in the first place, therefore the one bond Pt-P coupling constants of P(cis) and P(trans) reflect the cis and trans influences of X. The compounds [PtBr(PPh3)3](BF4) (2), [PtI(PPh3)3](BF4) (3), [Pt(AcO)(PPh3)3](BF4) (4), [Pt(NO3)(PPh3)3](BF4) (5), and the two isomers [Pt(NO2-O)(PPh3)3](BF4) (6a) and [Pt(NO2-N)(PPh3)3](BF4) (6b) have been newly synthesised and the crystal structures of 2 and 4·CH2Cl2·0.25C3H6O have been determined. From the 1JPtP values of all compounds we have deduced the series: I > Br > Cl > NO3 > ONO > F > AcO > NO2 > H > Me (cis influence) and Me > H > NO2 > AcO > I > ONO > Br > Cl > F > NO3 (trans influence). These sequences are like those obtained for the (neutral) cis- and trans-[PtClX(PPh3)2] derivatives, showing that there is no dependence on the charge of the complexes. On the contrary, the weights of both influences, relative to those of X = Cl, were found to depend on the charge and nature of the complex.  相似文献   

6.
Sulfated polysaccharides potently inhibit the infectivity of herpes simplex virus (HSV) in cultured cells. In this study, we have analyzed sulfated xylogalactofucan and alginic acid containing fractions generated from Laminaria angustata, a marine alga. The xylogalactofucan that has apparent molecular mass of 56 ± 5 kDa and unusually low sulfate content contains, inter alia, 1,3-, 1,4- and 1,2-linked fucopyranosyl residues. The algin (molecular mass: 32 ± 5 kDa) contains gulo- (55.5%) and mannuronic (44.5%) acid residues. Introduction of sulfate groups enhanced the macromolecules capability to inhibit the infection of cells by HSV-1. The 50% inhibitory concentration (IC50) values of these macromolecules against HSV-1 were in the range of 0.2-25 μg ml−1 and they lacked cytotoxicity at concentrations up to 1000 μg ml−1. The sulfate content appeared to be an important hallmark of anti-HSV-1 activity. Our results suggest the feasibility of inhibiting HSV attachment to cells by direct interaction of polysaccharides with viral particles.  相似文献   

7.
Industrial wastewater treatment comprises several processes to fulfill the discharge permits or to enable the reuse of wastewater. For tannery wastewater, constructed wetlands (CWs) may be an interesting treatment option. Two-stage series of horizontal subsurface flow CWs with Phragmites australis (UP series) and Typha latifolia (UT series) provided high removal of organics from tannery wastewater, up to 88% of biochemical oxygen demand (BOD5) (from an inlet of 420 to 1000 mg L−1) and 92% of chemical oxygen demand (COD) (from an inlet of 808 to 2449 mg L−1), and of other contaminants, such as nitrogen, operating at hydraulic retention times of 2, 5 and 7 days. No significant (P < 0.05) differences in performance were found between both the series. Overall mass removals of up to 1294 kg COD ha−1 d−1 and 529 kg BOD5 ha−1 d−1 were achieved for a loading ranging from 242 to 1925 kg COD ha−1 d−1 and from 126 to 900 kg BOD5 ha−1 d−1. Plants were resilient to the conditions imposed, however P. australis exceeded T. latifolia in terms of propagation.  相似文献   

8.
The preparation and characterization of manganese(III) complexes containing the quadridenate ligand, N,N′-bis(aminobenzylidene)-1,2-ethanediamine (H2amben), and its previously unreported analogue, N,N′-bis(2-amino-5-nitro-benzylidene)-1,2-ethanediamine (H2nitroamben), are described. The new manganese(III) halide/pseudohalide complexes, Mn(amben)X · nH2O and Mn(nitroamben)X · nH2O (X = Cl, Br, I, NCS; n =  0.5 or 1), were isolated as red-brown, microcrystalline solids, which were characterized fully.  相似文献   

9.
The first [Pd(Ln)2(ox)] xH2O oxalato(ox) complexes involving 2-chloro-N6-(benzyl)-9-isopropyladenine (L1; complex 1), 2-chloro-N6-(4-methoxybenzyl)-9-isopropyladenine (L2; 2), 2-chloro-N6-(2,3-dimethoxybenzyl)-9-isopropyladenine (L3; 3), 2-chloro-N6-(2,4-dimethoxybenzyl)-9-isopropyladenine (L4; 4), and 2-chloro-N6-(4-methylbenzyl)-9-isopropyladenine (L5; 5) have been synthesized by the reactions of potassium bis(oxalato)palladate(II) dihydrate, [K2Pd(ox)2]·2H2O, with the mentioned organic compounds (H2ox = oxalic acid; x = 0 for 1-3 and 5 or 2 for 4). Elemental analyses (C, H, N), FTIR, Raman and NMR (1H, 13C, 15N) spectroscopies, conductivity measurements and thermal studies (thermogravimetric and differential thermal analyses, TG/DTA) have been used to characterize the prepared complexes. The molecular structures of [Pd(L2)2(ox)] (2) and [Pd(L5)2(ox)]·L5·Me2CO (5·L5·Me2CO) have been determined by a single crystal X-ray analysis. The geometry of these complexes is slightly distorted square-planar with two appropriate Ln (n = 2 or 5) molecules mutually arranged in the head-to-head (2) or head-to-tail (5) orientation. The Ln ligands are coordinated to the central Pd(II) ion via the N7 atoms. The same conclusions regarding the binding properties of L1-L5 ligands can be made based on multinuclear NMR spectra. In vitro cytotoxicity of the complexes 1-5 has been evaluated against human chronic myelogenous leukaemia (K562) and human breast adenocarcinoma (MCF7) cancer cell lines. Significant cytotoxicity has been determined for the complexes 3 (IC50 = 6.2 μM) and 5 (IC50 = 6.8 μM) on the MCF7 cell line, which is even better than that found for the well-known and widely-used platinum-bearing antineoplastic drugs, i.e. oxaliplatin and cisplatin.  相似文献   

10.
Fucogalactans from edible Agaricus bisporus (RFP-Ab) and wild Lactarius rufus (RFP-Lr) mushrooms were obtained on aqueous extraction followed by purification. RFP-Ab had Mw 43.8 × 104 g mol−1 and RFP-Lr Mw 1.4 × 104 g mol−1. RFP-Lr had a (1 → 6)-linked α-d-Galp main-chain partially substituted at O-2 by nonreducing end-units of α-l-Fucp (29%). While RFP-Ab had a similar main chain, it was partially substituted at O-2 by nonreducing end-units of α-l-Fucp (2.8%) and β-d-Galp (14.5%), and partially methylated at HO-3. Both RFP-Lr and RFP-Ab were tested in mice against polymicrobial sepsis. Lethality rate, myeloperoxidase (MPO) activity and cytokine levels were determined. It was observed a reduction in late mortality rate by 62.5% and 50%, respectively, prevention of neutrophil accumulation in ileum and decreasing in TNF-α and IL-1β serum levels.  相似文献   

11.
To compare the cytotoxicities and the DNA-binding properties in tetranuclear complexes with different bridging ligands, two tetracopper(II) complexes with formulae of [Cu4(oxbe)2Cl2(bpy)2]·4H2O (1) and [Cu4(oxbm)2Cl2(bpy)2]·2H2O (2) were synthesized, where H3oxbe and H3oxbm stand for N-benzoato-N′-(2-aminoethyl)oxamide and N-benzoato-N′-(1,2-propanediamine)oxamide, respectively, and bpy is 2,2′-bipyridine. Complex 1 was characterized by elemental analyses, IR and electronic spectra and single-crystal X-ray diffraction. The crystal structure reveals the presence of the circular tetranuclear copper(II) cations which are assembled by a pair of cis-oxamido-bridged dinuclear copper(II) units through carboxyl bridges. The crystal structure of complex 2 has been reported in our previous paper. However, the bioactivities were not studied. Cytotoxicities experiments reveal that both the two complexes exhibit cytotoxic effects against human hepatocellular carcinoma cell SMMC-7721 and human lung adenocarcinoma cell A549, and complex 1 has the better activities than those of complex 2. The results of the interactions between the two complexes and herring sperm DNA (HS-DNA) suggest that the two complexes interact with HS-DNA in the mode of intercalation with the intrinsic binding constants of 3.93 × 104 M−1 (1) and 2.48 × 104 M−1 (2). These results indicated that the bridging ligands may play an important role in the cytotoxicities and the DNA-binding properties of tetranuclear complexes.  相似文献   

12.
Ligands containing the 2-organochalcogenomethylpyridine motif with substituents in the 4- or 6-position of the pyridyl ring, R4,R6-pyCH2ER1 [R4 = R6 = H, ER1 = SMe (1), SeMe (2), SPh (6), SePh (7); R4 = Me, R6 = H, ER1 = SMe (3), SPh (8), SePh (9); R4 = H, R6 = Me, ER1 = SMe (4), SPh (10), SePh (11); R4 = H, R6 = Ph, ER1 = SMe (5), SPh (12), SePh (13)] are obtained on the reaction of R4,R6-pyMe with LiBun followed by R1EER1. On reaction with PdCl2(NCMe)2, the ligands with a 6-phenyl substituent form cyclopalladated species PdCl{6-(o-C6H4)pyCH2ER1-C,N,E} (5a, 12a, 13a) with the structure of 13a (ER1 = SePh) confirmed by X-ray crystallography; other ligands form complexes of stoichiometry PdCl2(R4,R6-pyCH2ER1). Complexes with R6 = H are monomeric with N,E-bidentate configurations, confirmed by structural analysis for 3a (R4 = Me, ER1 = SMe), 7a (R4 = H, ER1 = SePh) and 9a (R4 = Me, ER1 = SePh). Two of the 6-methyl substituted complexes examined by X-ray crystallography are oligomeric with trans-PdCl2(N,E) motifs and bridging ligands, trimeric [PdCl2(μ-6-MepyCH2SPh-N,S)]3 (10a) and dimeric [PdCl2(μ-6-MepyCH2SePh-N,Se)]2 (11a). This behaviour is attributed to avoidance of the Me···Cl interaction that would occur in the cis-bidentate configuration if the pyridyl plane had the same orientation with respect to the coordination plane as observed for 3a, 7a and 9a [dihedral angles 8.0(2)-16.8(2)°]. When examined as precatalysts for the Mizoroki-Heck reaction of n-butyl acrylate with aryl halides in N,N-dimethylacetamide at 120 °C, the complexes exhibit the anticipated trends in yield (ArI > ArBr > ArCl, higher yield for electron withdrawing substituents in 4-RC6H4Br and 4-RC6H4Cl). The most active precatalysts are PdCl2(R4-pyCH2SMe-N,S) (R = H (1a), Me (3a)); complexes of the selenium containing ligands exhibit very low activity. For closely related ligands, the changes SMe to SPh, 6-H to 6-Me, and 6-H to 6-Ph lead to lower activity, consistent with involvement of both the pyridyl and chalcogen donors in reactions involving aryl bromides. The precatalyst PdCl2(pyCH2SMe-N,S) (1a) exhibits higher activity for the reaction of aryl chlorides in Bun4NCl at 120 °C as a solvent under non-aqueous ionic liquid (NAIL) conditions.  相似文献   

13.
Synthesis, spectroscopic and magnetic properties, and X-ray crystal structures of two copper(II) polymers Cu(2-qic)Br (2-qic = quinoline-2-carboxylate) (1) and Cu(2-pic)Br (2-pic = pyridine-2-carboxylate) (2) are described. These compounds are isostructural with Cu(2-qic)Cl and Cu(2-pic)Cl, respectively, the X-ray crystal structures of which were reported recently. Both complexes are polynuclear copper(II) compounds (1D and 2D, respectively) based on syn-anti carboxylate bridges and additionally on linear monobromo- (in 1) and dibromo-bridging (in 2) motifs. The magnetic properties were investigated in the temperature range 1.8-300 K. They reveal the occurrence of strong antiferromagnetic coupling (J1 = −102.5 cm−1) through the single bromo-bridge in 1, which is much stronger than that transmitted by the single chloro-bridge (J = −57.0 cm−1). Very weak ferromagnetic interaction through the syn-anti carboxylate bridge J2 is expected as it was observed in isomorphous Cu(2-qic)Cl (J = 0.37 cm−1). For 2 a weak ferromagnetic couplings through the syn-anti carboxylate (zJ′ = 1.35 cm−1) and dibromo-bridges (J = 8.31 cm−1) were found. The experimental results indicate that the observed ferromagnetic exchange through dibromo-bridge is weaker than that in the chloride analog (J = 15.0 cm−1). The magnitude of magnetic interactions is discussed on the basis of structural data of compounds 1 and 2 and their halide analogues.  相似文献   

14.
Synthesis, physical properties and X-ray structure of a hydrated tetranuclear copper(II) complex [Cu4(μ-diph)2(μ-H2O)2(O2CCH3)4(H2O)2]·4H2O with N,N′-bis(picolinoyl)hydrazine (H2diph) are reported. The centrosymmetric complex has two types of copper(II) centres with distorted square-pyramidal N2O3 coordination spheres. The dinucleating trans planar diph2− ligands are parallel to each other and act as N2O-donor to one metal centre and N2-donor to the other metal centre. The complex has a rectangular {Cu4(μ-N-N)2(μ-OH2)2} core with Cu···Cu distances as 4.834(1) and 3.762(1) Å. Solid state as well as solution electronic spectra show several transitions in the wavelength range 700-280 nm. The room temperature (298 K) solid state magnetic moment is 3.55 μB. The powder EPR spectra at 298 and 130 K are very similar and axial (g = 2.25 and g = 2.08) in character.  相似文献   

15.
This experimental study quantified and compared particle-mixing and solute transport by the polychaetes Marenzelleria neglecta (2 g ww, 3200 ind. m− 2) and Hediste diversicolor (2 g ww, 800 ind. m− 2) in Baltic Sea sediments. Particle tracers (luminophores) were added to the sediment surface and their vertical distribution in the sediment was measured after 10 d. The rate of particle mixing was quantified using a gallery-diffusion model calculating the biodiffusion coefficient Db and the non-local transport parameter r. Bioirrigation was measured by adding an inert solute tracer (bromide) to the overlying water 1, 1.5 and 2 d before the end of the experiment, and quantified by calculating the net bromide flux and fitting the bromide profiles to a 1D diffusion model providing an apparent biodiffusion coefficient Da. The two polychaete worms displayed similar particle-mixing and solute transport efficiencies (based on total biomass) despite different modes of bioturbation. However, H. diversicolor was a more efficient particle-reworker and M. neglecta a more efficient bioirrigator, on an individual level. H. diversicolor buried a higher percentage (13%) of luminophores below the top 0.5 cm surface layer than M. neglecta (6%). Db did not differ between the two species (2.4 × 10− 3 cm2 d− 1) indicating a similar rate of diffusive mixing of the top sediment, however, the non-local transport parameter r was 2.5 y− 1 for H. diversicolor and zero for M. neglecta, suggesting no significant particle-transport below the biodiffusive layer by M. neglecta. The average individual net bromide fluxes obtained were ca. 0.01 mL min− 1 for H. diversicolor and 0.003 mL min− 1 for M. neglecta, corresponding to an area-specific rate of ca. 12 L m− 2 d− 1 at the used densities. Da did not differ between the two polychaetes, suggesting a higher individual solute exchange efficiency of M. neglecta considering the much higher ventilation rates reported for H. diversicolor than for Marenzelleria sp. The ongoing colonization of Baltic Sea sediments by M. neglecta at high densities may thus lead to an enhanced soluble release of both nutrients and contaminants. These results add information to the understanding of the potential effects of the invasion of M. neglecta on sediment biogeochemistry when competing with and/or replacing native species.  相似文献   

16.
New heterodinuclear ZnII/NiII (1) and homodinuclear NiII/NiII (2) water-soluble and air stable compounds of general formula [M(H2O)6][M′(dipic)2] · mH2O have been easily prepared by self-assembly of the corresponding metal(II) nitrates with dipicolinic acid (H2dipic) in water solution at room temperature.  The compounds have been characterized by IR, UV/Vis and atomic absorption spectroscopies, elemental and X-ray single crystal diffraction (for 1 · 4H2O and 2 · 5H2O) analyses.  3D infinite polymeric networks are formed via extensive hydrogen bonding interactions involving all coordinated and crystallization water molecules, and all dipicolinate oxygens, thus contributing to additional stabilization of dimeric units, metal-organic chains and 2D layers.  In 1 · 4H2O, the latter represent a rectangular-grid 2D framework with multiple channels if viewed along the c crystallographic axis, while in 2 · 5H2O intercalated crystallization water molecules are associated to form acyclic nonplanar hexameric water clusters and water dimers which occupy voids in the host metal-organic matrix, with a structure stabilizing effect via host-guest interactions.  The hexameric cluster extends to the larger (H2O)10 one with an unusual geometry (acyclic helical octamer with two pendent water molecules) by taking into account the hydrogen bonds to water ligands in [Ni(H2O)6]2+.  The obtained Zn/Ni compound 1 relates to the recently reported family of heterodimetallic complexes [M(H2O)5M′(dipic)2] · mH2O (M/M′ = Cu/Co, Cu/Ni, Cu/Zn, Zn/Co, Ni/Co, m = 2, 3), what now allows to establish the orders of the metal affinity towards the formation of chelates with dipicolinic acid (CoII > NiII > ZnII > CuII) or aqua species (CoII < NiII < ZnII < CuII).  相似文献   

17.
2,2′-Dipyridylketone (dpk), when acting as a chelating ligand for PdII or PtII, is in slow equilibrium with its corresponding gem-diol form (dpk·H2O). In D2O, equilibrium constants K = (dpk·H2O)/(dpk) change from ca. 0.04 for the free ligand to ca. 3 in the corresponding complexes with cis-[Pt(H2O)2]2+. In solution, species of both ligands can be identified and differentiated by 1H NMR spectroscopy, and in the trinuclear μ-OH bridged PtII complex [Pt3(μ-OH)3(dpk·H2O)2(dpk)](NO3)3·4.5H2O (4), both types of ligands are present simultaneously in a ratio of (dpk·H2O):(dpk) = 2. As demonstrated with a series of PdII complexes containing dpk·H2O and dpk ligands, a straightforward differentiation is possible when DMSO-d6 is used as solvent, because then also the OH protons of dpk·H2O are observable. It is also shown that monocrystalline [PdCl2(dpk·H2O)] (1), when dissolved in DMSO-d6, partially converts, with loss of H2O, to [PdCl2(dpk)].  相似文献   

18.
The mononuclear cationic cobalt(III) complex 1 [Co(L)2]+ [where HL is H2N(CH2)2NC(Ph)C6H2(Me)(OH)COPh] has been obtained by the condensation of 4-methyl-2,6-dibenzoylphenol and ethane-1,2-diamine in the presence of CoCl2 · 6H2O and isolated as the chloride solvate {1 · Cl · 2H2O · EtOH}. The water and ethanol do not form part of the cobalt(III) pseudo-octahedral [Co(L)2]+ coordination sphere, which is cis-CoN4O2 with the NNO-ligands mer. Compound 1 has been characterised by mass spectrometry, IR, electronic, 1H and 13C NMR spectroscopy, conductivity measurements, elemental analysis, TGA, cyclic voltammetry and an X-ray structural determination. The average Co-N and Co-O distances are, respectively, 1.929(4) and 1.882(3) Å. The N?N intraligand bite distance is 2.73(4) Å and the N-Co-N and O-Co-O angles are, respectively, 86.2(15)° and 93.3(13)°. Cyclic voltammetric studies of complex 1 indicate an irreversible cathodic peak (Epc, ca. −0.61 V) corresponding to the reduction of cobalt(III) to cobalt(II). Absorption titration experiments gave a binding constant for DNA interaction of 1.4 × 104 M−1 and a binding site size 0.16 base pairs.  相似文献   

19.
The orthorhombically crystallizing salts Rb2[B12(OH)12]·2H2O (= 1576.81(9), b = 813.08(5), c = 1245.32(7) pm) and Rb2[B12(OH)12]·2H2O2 (= 1616.54(9), b = 814.29(5), c = 1260.12(7) pm) could be prepared from Rb2[B12H12] and hydrogen peroxide. Both crystal structures were determined by X-ray single crystal diffraction and refined in the space group Cmce. They are not isostructural to the other compounds containing icosahedral dodecahydroxo-closo-dodecaborate dianions [B12(OH)12]2− and potassium, rubidium or cesium cations already known to literature, but both title compounds crystallize quasi-isotypically exhibiting Rb+ cations in 10-fold oxygen coordination. The hydrogen peroxide adduct (Rb2[B12(OH)12]·2H2O2) is explosive on shock and heat, while the hydrate (Rb2[B12(OH)12]·2H2O) is not.  相似文献   

20.
The utility of p-sulphonatocalix[4]arene (s-CX[4]) as a drug delivery vehicle for multinuclear platinum anticancer agents, using trans-[{PtCl(NH3)2}2μ-dpzm]2+ (di-Pt; where dpzm = 4,4′-dipyrazolylmethane) as a model complex, has been examined using 1H nuclear magnetic resonance, electrospray ionisation mass spectrometry, molecular modelling and in vitro growth inhibition assays. s-CX[4] binds di-Pt in a side-on fashion in a ratio of 1:1, with the dpzm ligand of the metal complex located within the s-CX[4] cavity with binding further stabilised by ion-ion interactions and hydrogen bonding between the metal complex am(m)ine groups and the s-CX[4] sulphate groups. Partial encapsulation of di-Pt within the cavity does not prevent binding of 5′-guanosine monophosphate to the metal complex. When bound to two individual guanosine molecules, di-Pt also remains partially bound by s-CX[4]. The cytotoxicity of free di-Pt and s-CX[4] and their host guest complex was examined using in vitro growth inhibition assays in the A2780 and A2780cis human ovarian cancer cell lines. Free di-Pt has an IC50 of 100 and 60 μM, respectively, in the cell lines, which is significantly less active than cisplatin (1.9 and 8.1 μM, respectively). s-CX[4] displays no cytotoxicity at concentrations up to 1.5 mM and does not affect the cytotoxicity of di-Pt, probably because its low binding constant to the metal complex (6.8 × 104 M−1) means the host-guest complex is mostly disassociated at biologically relevant concentrations.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号