Metal-Based Drugs最新文献

In this study we compared the effects of two previously described antimitochondrial gold complexes, that is, [A] [Au(dppe)(2)]Cl and [B] [Au(d4pype)(2)]Cl with two novel lipophilic cations, that is, [C] [Au(dpmaaH(2))(dpmaaSnMe(2))]Cl and [D] [Au(dpmaaSnMe(2))(2)]Cl as antimitochondrial agents. The results of this study indicate that [C] and [D] have intermediate partition coefficients and exhibited a selective uptake by cells. They exhibited a higher selectivity for the various cell lines than [A] but were more cytotoxic than [B]. There is a significant correlation between the cytotoxic potential of [A], [B], [C], and [D] and their octanol/water partition coefficients in both MCF-7 (breast cancer) and MCF-12A (nonmalignant breast) cells, whereas their cytotoxic potential and ability to induce the release of cytochrome c correlated only in the case of the MCF-12A cells. Complexes [C] and [D] are promising new chemotherapeutic drugs. These compounds target the mitochondrial membranes of certain cancer cells exploiting the differences between the mitochondrial membrane potential of these cells and normal cells. Although the concentrations of these compounds necessary to eradicate cancer cells are very high, the results provide a basis for the synthesis of a new family of compounds with intermediate partition coefficients compared to [A] and [B] but with increased activity against cancer cells.

A molecularly imprinted polymer (MIP) for tri-O-acetyladenosine (TOAA), PPM(TOAA), was prepared by the combined use of methacrylic acid (MAA) and Zn(II)tetra(4'-methacryloxyphenoxy) phthalocyanine as functional monomers. This MIP exhibited a higher binding ability for TOAA compared to the MIP prepared using only MAA, PM(TOAA), in batch rebinding tests. Scatchard analysis gave a higher association constant of PPM(TOAA) for TOAA (2.96x104 M-1) than that of PM(TOAA) (1.48x104 M-1). The MIP prepared using only the zinc-phthalocyanine, PP(TOAA), did not show any binding capacity for TOAA. This means that the phthalocyanine in the MIP contributes to higher affinities, although it barely interacts with TOAA. Since selectivity for this kind of MIPs is more important than binding affinity, the binding of TOAA and a structurally related compound, tri-O-acetyluridine (TOAU), on the polymers was investigated. Both PPM(TOAA) and PM(TOAA) exhibited binding affinities for TOAA while they did not show any binding capacity for TOAU.

Platinum drugs continue to be major chemotherapy drugs for cancer treatment. Nevertheless, acquired or intrinsic resistance to these compounds is common in human tumors. One important mechanism for this resistance is the avoidance of cells entering the apoptotic pathway. Nuclear factor-kappa B (NF-kappa B, NF-kappaB) is a pleiotropic transcription factor key in determining the death threshold of human cells. This factor is important in the final response of cells to platinum drugs, as exemplified by in vitro and in vivo models showing that inhibition of NF-kappaB sensitizes cancer cells to the effects of these drugs. New approaches focusing on the inhibition of NF-kappaB could help to minimize or even eliminate intrinsic or acquired resistance to platinum drugs.

Helicobacter pylori (H. pylori) is a widespread human pathogen causing peptic ulcers and chronic gastritis. Maintaining nickel homeostasis is crucial for the establishment of H. pylori infection in humans. We used immobilized-nickel affinity chromatography to isolate Ni-related proteins from H. pylori cell extracts. Two-dimensional gel electrophoresis and mass spectrometry were employed to separate and identify twenty two Ni-interacting proteins in H. pylori. These Ni-interacting proteins can be classified into several general functional categories, including cellular processes (HspA, HspB, TsaA, and NapA), enzymes (Urease, Fumarase, GuaB, Cad, PPase, and DmpI), membrane-associated proteins (OM jhp1427 and HpaA), iron storage protein (Pfr), and hypothetical proteins (HP0271, HP jhp0216, HP jhp0301, HP0721, HP0614, and HP jhp0118). The implication of these proteins in nickel homeostasis is discussed.

Two novel cobalt(III) pyridine complexes (1)[Co(en)2(py)2]3+ and (2)[Co(en)2(mepy)2]3+ (en=ethylenediamine, py=pyridine, and mepy=methylpyridine) have been synthesized and characterized. The interaction of these complexes with calf thymus DNA was investigated by absorption, emission spectroscopy, viscosity measurements, DNA melting, and DNA photocleavage. Results suggest that the two complexes bind to DNA via groove mode and complex 2 binds more strongly to CT DNA than complex 1. Moreover, these Co(III) complexes have been found to promote the photocleavage of plasmid DNA pBR322 under irradiation at 365 nm, cytotoxicity results of complexes are also showing anticancer activity.

The porphyrazines (pzs), a class of porphyrin analogues, are being investigated for their potential use as tumor imaging/therapeutic agents. We here examine six peripherally-functionalized M[pz(AnB4-n)] pzs with n=4, 3, or 2 (in a trans conformation) and M = H2 or Zn, where A is an [S((CH2)2O)4Me]2 unit and B is a fused beta,beta'-diisopropyloxybenzo group. Cell viability/proliferation assays and fluorescence microscopy were carried out in both tumor and normal cells. Dark toxicity studies disclosed that four of the compounds exhibited toxicity in both normal and tumor cells; one was nontoxic in both normal and tumor cells, and one was selectively toxic to normal cells. Additionally, three of the pzs showed enhanced photo-induced toxicity with these effects in some cases being observed at treatment concentrations of up to ten-fold lower than that needed for a response in Photofrin. All six compounds were preferentially absorbed by tumor cells, suggesting that they have potential as in vitro diagnostic agents and as aids in the isolation and purification of aberrant cells from pathological specimens. In particular, two promising diagnostic candidates have been identified as part of this work.

The synthesis, structure, electrochemistry, and biological studies of Co(II), Ni(II), Cu(II), and Zn(II) complexes of thiocarbohydrazone ligand are described. The ligand is synthesized starting from thiocarbohydrazide and isatin. It is evident from the IR data that in all the complexes, only one part of the ligand is coordinated to the metal ion resulting mononuclear complexes. The ligand coordinates essentially through the carbonyl oxygen of the isatin fragment, the nitrogen atom of the azomethine group, and sulfur atom after deprotonation to give five membered rings. H1 NMR spectrum of the ligand shows only one set of signals for the aromatic protons, while the NH of isatin and NH of hydrazone give rise to two different singlets in the 11-14 ppm range. The formulations, [Cu(L)Cl].2H2O, [Cu(L)(CH3COO)].2H2O, [Ni(L)Cl], [Ni(L)(CH3COO)], [Co(L2)], and [Zn(L2)].2H2O are in accordance with elemental analyses, physical, and spectroscopic measurements. The complexes are soluble in organic solvents. Molar conductance values in DMF indicate the nonelectrolytic nature of the complexes. Copper complex displays quasireversible cyclic voltametric responses with Ep near -0.659 v and 0.504 v Vs Ag/AgCl at the scan rate of 0.1 V/s. Copper(II) complexes show a single line EPR signals. For the observed magnetic moment and electronic spectral data possible explanation has been discussed. From all the available data, the probable structures for the complexes have been proposed. The compounds synthesized in present study have shown promising cytotoxic activity when screened using the in vitro method and at the same time were shown to have good activity when tested using the Ehrlich ascites carcinoma (EAC) model. The antimicrobial screening showed that the cobalt complex possesses enhanced antimicrobial activity towards fungi.

A kinetic study of the aqua substitution in the [TcO(OH(2))(CN)(4)](-) complex by different thiourea ligands (TU = thiourea, NMTU = N-methyl thiourea, NNDMTU = N, N'-dimethylthiourea) yielded second-order formation rate constants (25 degrees C) as follows [NNDMTU, NMTU, TU, respectively]: k(f) = 11.5 +/- 0.1, 11.38 +/- 0.04, and 7.4 +/- 0.1 M(-1)s(-1), with activation parameters: Delta H(#) (k(f) ) : 55 +/- 2, 42 +/- 3, 35 +/- 5 kJ mol(-1); DeltaS(#) (k(f) ) : - 40 +/- 8, - 84 +/- 11, - 110 +/- 17 J K(-1)mol(-1). A subsequent high-pressure investigation of the aqua substitution in the [ReO(OH(2))(CN)(4)](-) and [TcO(OH(2))(CN)(4)](-) complexes by selected entering ligands yielded DeltaV(#) (k(f) ) values as follows: Re(V): -1.7 +/- 0.3(NCS(-)), -22.1 +/- 0.9 (TU) and for Tc(V): -3.5 +/- 0.3(NCS(-)), -14 +/- 1 (NNDMTU), and -6.0 +/- 0.5 (TU) cm(3)mol (-1), respectively. These results point to an interchange associative mechanism for the negative NCS(-) as entering group but even a pure associative mechanism for the neutral thiourea ligands.

New bidentate or tridentate Schiff bases and their VO(II) and Co(II) complexes formed by the condensation of methyl isobutyl ketone with nicotinamide (mna)/2-amino-4-chlorophenol (map) and 2-hydroxy acetophenone with nicotinamide (han)/isoniazide (hai). Physicochemical characterization has been carried out to determine the structure of the complexes. The FAB mass and thermal data show degradation pattern of the complexes. XRD analysis reveals that all the studied complexes crystallize as tetragonal crystal system. Some of the complexes have been screened for their antimicrobial activity by the well diffusion technique using DMSO as solvent on different species of pathogenic bacteria/fungi, that is, E. coli, S. aureus, S. fecalis, A. niger, T. polysporum, and their antimicrobial potency have been discussed. It has been found that all the complexes are antimicrobially active and show higher activity than the free ligand. Metal chelation affects significantly the antimicrobial/bioactive behavior of the organic ligands.

From the carbolithiation of 6-N,N-dimethylamino fulvene (3) and 2,4[bis(N,N-dimethylamino)methyl]-N-methylpyrrolyl lithium (2a), N-(N',N'-dimethylaminomethyl)benzimidazolyl lithium (2b), or p-(N,N-dimethylamino)methylphenyl lithium (2c), the corresponding lithium cyclopentadienide intermediate (4a-c) was formed. These three lithiated intermediates underwent a transmetallation reaction with TiCl(4') resulting in N,N-dimethylamino-functionalised titanocenes 5a-c. When these titanocenes were tested against a pig kidney epithelial cell line (LLC-PK), the IC50 values obtained were of 23, and 52 muM for titanocenes 5a and 5b, respectively. The most cytotoxic titanocene in this paper, 5c with an IC50 value of 13 muM, was found to be approximately two times less cytotoxic than its analogue Titanocene C (IC50=5.5 muM) and almost four times less cytotoxic than cisplatin, which showed an IC50 value of 3.3 muM when tested on the LLC-PK cell line.