Ru(II)-diphosphine/N,S-mercapto complexes and their anti-melanoma properties.

We have synthesized and characterized a novel series of ruthenium complexes with formulas [RuCl(N-S)(dppm)]PF (Ru1), [Ru(N-S)(dppm)]PF (Ru2), [Ru(N-S)(dppe)]PF (Ru3), [Ru(N-S)(dppen)]PF (Ru4), [Ru(N-S)(bpy)]PF (Ru5). In these formulas, N-S or S represents H2mq (2-mercapto-4(3)-quinazoline); dppe (1,2'-bis(diphenylphosphine)ethane), dppm (1,1'-bis(diphenylphosphine)methane), or dppen (1,2'-bis(diphenylphosphine)ethene); and bpy refers to 2,2'-bipyridine. We have also compared the cytotoxicity of cisplatin with these ruthenium complexes to murine melanoma cells (B16-F10), human melanoma cells (A-375), and the non-tumoral human keratinocyte cell line (HaCat).

Pd(II)/diphosphine/curcumin complexes as potential anticancer agents.

Palladium(II) complexes have stimulated research interest mainly due to their cytotoxicity against various cancer cell lines and their low cytotoxicity in healthy cells. Thus, in this work, we combined Pd(II)/phosphine systems with the natural product curcumin as a ligand, obtaining a series of complexes, [Pd(cur)(PPh)]PF (A1), [Pd(cur)(dppe)]PF (A2), [Pd(cur)(dppp)]PF (A3), [Pd(cur)(dppb)]PF (A4) and [Pd(cur)(dppf)]PF (A5), where dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane, dppb = 1,4-bis(diphenylphosphino)butane, and dppf = 1,1'-bis(diphenylphosphino)ferrocene (P-P), which were characterized by elemental analysis, molar conductivity analysis, and mass, NMR (H, C, P{H}), UV-vis, and IR spectroscopies, and four of them (A1, A2, A4, and A5) by X-ray crystallography. The cell viability of the complexes A1-A5, cisplatin, and the free ligand curcumin against MDA-MB-231 (human triple-negative breast tumor cells), SK-BR-3 (human breast tumor cells), A549 (human lung tumor cells), MRC-5 (non-tumor human lung cells), A2780 (human ovarian carcinoma cells), and A2780cis (cisplatin-resistant human ovarian carcinoma cells), was evaluated by the MTT colorimetric assay.

Biomimetic catalysis of nitrite reductase enzyme using copper complexes in chemical and electrochemical reduction of nitrite.

Copper nitrite reductase mimetics were synthesized using three new tridentate ligands sharing the same ,, motif of coordination. The ligands were based on L-proline modifications, attaching a pyridine and a triazole to the pyrrolidine ring, and differ by a pendant group (R = phenyl, -butyl and -propan-1-ol). All complexes coordinate nitrite, as evidenced by cyclic voltammetry, UV-Vis, FTIR and electron paramagnetic resonance (EPR) spectroscopies.

Cytotoxic and antiparasitic activities of diphosphine-metal complexes of group 10 containing acylthiourea as ligands.

In this work, group 10 transition metal complexes bearing dppe [1,2-bis(diphenylphosphino)ethane] and acylthiourea ligands were evaluated for their cytotoxic and antiparasitic activities. Six new complexes with a general formula [M(L)(dppe)]BF [where M = Ni, Pd or Pt; L = N, N'-dimethyl-N-benzoyl thiourea (L) or N, N'-dimethyl-N-tiofenyl thiourea (L) were synthesized and characterized by infrared, NMR (P{H}, H and C{H}) spectroscopies, elemental analysis and molar conductivity. The structures of the complexes were confirmed by X-ray diffraction technique.

Ruthenium(II)-diphosphine complexes containing acylthiourea ligands are effective against lung and breast cancers.

We have synthesized and characterized three new ruthenium(II) diphosphine complexes containing an acylthiourea ligand, with the general formula [Ru(DPEPhos)(O,S)(bipy)]PF, where DPEPhos = bis(2-(diphenylphosphino)phenyl)ether, bipy = 2,2'-bipyridine, and O,S = ,-dimethyl-'-(benzoyl)thiourea (1), ,-dimethyl-'-(furoyl)thiourea (2), and ,-dimethyl-'-(thiophenyl)thiourea (3), by several physicochemical techniques. We evaluated the ruthenium complexes for their cytotoxicity against two human cancer cell lines, A549 (lung) and MDA-MB-231 (breast), and two corresponding lines of non-cancer cells, MRC-5 (lung) and MCF-10A (breast). All the complexes are cytotoxic against the cancer cell lines; the IC values lie in the micromolar range (0.

Comparative Study of Antioxidant and Pro-Oxidant Properties of Homoleptic and Heteroleptic Copper Complexes with Amino Acids, Dipeptides and 1,10-Phenanthroline: The Quest for Antitumor Compounds.

In a search for new antitumoral agents, a series of homoleptic copper(II) complexes with amino acids and dipeptides, as well as heteroleptic complexes containing both dipeptides and 1,10-phenanthroline, were studied. Furthermore, a single-crystal structure containing alanyl-leucinato ([Cu(AlaLeu)(HO)(CO)]·PF·HO), which is the first homotrinuclear carbonato-bridged copper(II) complex with a dipeptide moiety, is presented. To assess possible antitumor action mechanisms, we focused on the comparative analysis of pro- and antioxidant behaviors.

New AlZn and AlCu dinuclear complexes: Phosphatase-like activity and cytotoxicity.

Herein, we report the synthesis and characterization of the first two Al(μ-OH)M (M = Zn (1) and Cu (2)) complexes with the unsymmetrical ligand HL{2-[[(2-hydroxybenzyl)(2-pyridylmethyl)]aminomethyl]-6-bis(pyridylmethyl)aminomethyl}-4-methylphenol. The complexes were characterized through elemental analysis, X-ray crystallography, IR spectroscopy, mass spectrometry and potentiometric titration. In addition, complex 2 was characterized by electronic spectroscopy.

Ruthenium(II) Phosphine/Mercapto Complexes: Their in Vitro Cytotoxicity Evaluation and Actions as Inhibitors of Topoisomerase and Proteasome Acting as Possible Triggers of Cell Death Induction.

In this paper, a series of new ruthenium complexes of the general formula [Ru(NS)(dpphpy)(dppb)]PF (-), where dpphpy = diphenyl-2-pyridylphosphine, NS ligands = 2-thiazoline-2-thiol (tzdt, ), 2-mercaptopyrimidine (pySm, ), and 4,6-diamino-2-mercaptopyrimidine (damp, ), and dppb = 1,4-bis(diphenylphosphino)butane, were synthesized and characterized by elemental analysis, spectroscopic techniques (IR, UV/visible, and 1D and 2D NMR), and X-ray diffraction. In the characterization, the correlation between the phosphorus atoms and their respective aromatic hydrogen atoms of the compounds in the assignment stands outs, by H-P HMBC experiments. The compounds show anticancer activities against A549 (lung) and MDA-MB-231 (breast) cancer cell lines, higher than the clinical drug cisplatin.

Selective Coordination Mode of Acylthiourea Ligands in Half-Sandwich Ru(II) Complexes and Their Cytotoxic Evaluation.

In this study, half-sandwich Ru(II) complexes containing acylthiourea ligands of the general type [Ru(η--cymene)(PPh)(S)Cl]PF (-) and [Ru(η--cymene)(PPh)(S-O)]PF (-) where S/S-O = -disubstituted acylthiourea were synthesized and characterized (via elemental analyses, IR spectroscopy, H NMR spectroscopy, C{H} NMR spectroscopy, and X-ray diffractometry), and their cytotoxic activity was evaluated. The different coordination modes of the acylthiourea ligands, monodentately via S (-) and bidentately via S,O (-), to ruthenium were modulated from different synthetic routes. The cytotoxicity of the complexes was evaluated in five human cell lines (DU-145, A549, MDA-MB-231, MRC-5, and MCF-10A) by MTT assay.

Non-mutagenic Ru(ii) complexes: cytotoxicity, topoisomerase IB inhibition, DNA and HSA binding.

Herein we discuss five ruthenium(ii) complexes with good cytotoxicity against cancer cells. These complexes are named [Ru(tzdt)(bipy)(dppb)]PF6 (1), [Ru(mmi)(bipy)(dppb)]PF6 (2), [Ru(dmp)(bipy)(dppb)]PF6 (3), [Ru(mpca)(bipy)(dppb)]PF6 (4) and [Ru(2mq)(bipy)(dppb)]PF6 (5), where tzdt = 1,3-thiazolidine-2-thione, mmi = mercapto-1-methyl-imidazole, dmp = 4,6-diamino-2-mercaptopyrimidine, mpca = 6-mercaptopyridine-3-carboxylic acid, 2mq = 2-mercapto-4(3H)-quinazolinone, bipy = 2,2'-bipyridine and dppb = 1,4-bis(diphenylphosphino)butane. In vitro cell culture experiments revealed significant cytotoxic activity for 1-5 against MDA-MB-231, MCF-7, A549, DU-145 and HepG2 tumor cells, higher than that for the standard anticancer drug cisplatin.

Light-activated generation of nitric oxide (NO) and sulfite anion radicals (SO˙) from a ruthenium(ii) nitrosylsulphito complex.

This manuscript describes the preparation of a new Ru(ii) nitrosylsulphito complex, trans-[Ru(NH)(isn)(N(O)SO)] (complex 1), its spectroscopic and structural characterization, photochemistry, and thermal reactivity. Complex 1 was obtained by the reaction of sulfite ions (SO) with the nitrosyl complex trans-[Ru(NH)(isn)(NO)] (complex 2) in aqueous solution resulting in the formation of the N-bonded nitrosylsulphito (N(O)SO) ligand. To the best of our knowledge, only four nitrosylsulphito metal complexes have been described so far (J.

Magnetic-field-tuned phase transition of a molecular material from the isolated-spin to the coupled-spin regime.

We report the preparation, X-ray structure, chemical properties, and electron paramagnetic resonance (EPR) studies at Q and X-bands and temperature (mainly) T = 293 K of powder and oriented single crystal samples of the new compound [Cu(N',N'-dimethyl-N'-benzoylthiourea)(2,2'-bipyridine)Cl], called CuBMB. The EPR spectra of single crystal samples at the Q-band display abrupt merging and narrowing of the peaks corresponding to two rotated copper sites as a function of magnetic field (B0) orientation. This behaviour indicates a quantum transition from an array of quasi-isolated spins to a quantum-entangled spin array associated with exchange narrowing processes and produced by weak intermolecular exchange interactions Ji between neighbour copper spins.

Carbonyl-heterobimetallic Ru(II)/Fe(II)-complexes containing polypyridyl ligands: Synthesis, characterization, cellular viability assays and interactions with biomolecules.

This paper describes on the interaction studies of carbonyl heterobimetallic compounds of Ru(II)/Fe(II) containing polypyridyl ligands, with general formula ct-[RuCl(CO)(N-N)(dppf)]PF, N-N = 1,10-phenanthroline (phen) 5; dipyrido[3,2-f:2',3'-h]quinoxaline (dpq) 6; dipyrido[3,2-a:2',3'-c]phenazine (dppz) 7; dipyrido[3,2-f:2',3'-h]quinoxalino[2,3-b]quinoxaline (dpqQX) 8 and dppf = 1,1'-bis(diphenylphosphino) ferrocene], with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA). Also, it describes the cellular viability assays of these complexes in tumorigenic and non-tumorigenic cell lines. The carbonyl complexes 5-8 and their respective precursors with formula cis-[RuCl(N-N)(dppf)], N-N = phen (1), dpq (2), dppz (3) and dpqQX (4), were characterized by elemental analysis and spectroscopic techniques (FTIR, UV-vis, H and P{H} NMR).

Hydrolysis reaction promotes changes in coordination mode of Ru(II)/acylthiourea organometallic complexes with cytotoxicity against human lung tumor cell lines.

In this study, Ru(II)-arene complexes with acylthiourea ligands of the type [Ru(η‑p‑cymene)(PPh)(T)Cl]PF(1-5) and [Ru(η‑p‑cymene)(PPh)(T)]PF(1a, 4a), where PPh = triphenylphosphine and T = N‑acyl‑N'(monosubstituted)thiourea, were synthesized and characterized, and their cytotoxic properties were also evaluated. 1a and 4a were obtained from the hydrolysis reaction of 1 and 4. All complexes showed unusual coordination modes for acylthiourea ligands, which are coordinated in a monodentate fashion (S) in 1-5, while they found to be bidentate (S,N), in 1a and 4a.

The trans-[Ru(PPh)(N,N-dimethyl-N'-thiophenylthioureato-kO,S)(bipy)]PF complex has pro-apoptotic effects on triple negative breast cancer cells and presents low toxicity in vivo.

Triple negative breast cancer (TNBC) is a heterogeneous subtype of breast tumors that does not exhibit the expression of estrogen and progesterone receptors, neither the amplification of the human epidermal growth factor receptor 2 (HER-2) gene. Despite all the advances in cancer treatments, the development of new anticancer drugs for TNBC tumors is still a challenge. There is an increasing interest in new agents to be used in cancer treatment.

Half sandwich Ru(ii)-acylthiourea complexes: DNA/HSA-binding, anti-migration and cell death in a human breast tumor cell line.

Organometallic ruthenium complexes as potential anticancer agents have been explored due to their suitable properties, such as stability in the solid state and in solution, water solubility and low toxicity. In this study, eight metal complexes of this class were synthesized, characterized and their important biological activities against a human breast tumor cell line (MDA-MB-231) were studied. Complexes 1-8 were obtained in good yields and have been characterized by satisfactory elemental analyses, IR, 1D and 2D H and C{H} NMR, UV-Vis spectroscopy, cyclic voltammetry, ESI-MS and X-ray diffractometry (1, 2, 3 and 6).

Understanding the conformational changes and molecular structure of furoyl thioureas upon substitution.

1-Acyl thioureas [RC(O)NHC(S)NRR] are shown to display conformational flexibility depending on the degree of substitution at the nitrogen atom. The conformational landscape and structural features for two closely related thioureas having R=2-furoyl have been studied. The un-substituted 2-furoyl thiourea (I) and its dimethyl analogue, i.

Ruthenium(II) complexes of 1,3-thiazolidine-2-thione: Cytotoxicity against tumor cells and anti-Trypanosoma cruzi activity enhanced upon combination with benznidazole.

Three new mixed and mononuclear Ru(II) complexes containing 1,3-thiazolidine-2-thione (tzdtH) were synthesized and characterized by spectroscopic analysis, molar conductivity, cyclic voltammetry, high-resolution electrospray ionization mass spectra and X-ray diffraction. The complexes presented unique stereochemistry and the proposed formulae are: [Ru(tzdt)(bipy)(dppb)]PF6 (1), cis-[Ru(tzdt)2(PPh3)2] (2) and trans-[Ru(tzdt)(PPh3)2(bipy)]PF6 (3), where dppb=1,4-bis(diphenylphosphino)butane and bipy=2,2'-bipyridine. These complexes demonstrated strong cytotoxicity against cancer cell lines when compared to cisplatin.

Ru(II)-based complexes with N-(acyl)-N',N'-(disubstituted)thiourea ligands: Synthesis, characterization, BSA- and DNA-binding studies of new cytotoxic agents against lung and prostate tumour cells.

Four ruthenium(II)-based complexes with N-(acyl)-N',N'-(disubstituted)thiourea derivatives (Th) were obtained. The compounds, with the general formula trans-[Ru(PPh3)2(Th)(bipy)]PF6, interact with bovine serum albumin (BSA) and DNA. BSA-binding constants, which were in the range of 3.

Synthesis, characterization, hydrolase and catecholase activity of a dinuclear iron(III) complex: Catalytic promiscuity.

Herein, we report the synthesis and characterization of the new di-iron(III) complex [(bbpmp)(H2O)(Cl)Fe(III)(μ-Ophenoxo)Fe(III)(H2O)Cl)]Cl (1), with the symmetrical ligand 2,6-bis{[(2-hydroxybenzyl)(pyridin-2-yl)methylamino]methyl}-4-methylphenol (H3bbpmp). Complexes 2 with the unsymmetrical ligand H2bpbpmp - {2-[[(2-hydroxybenzyl)(2-pyridylmethyl)]aminomethyl]-6-bis(pyridylmethyl) aminomethyl}-4-methylphenol and 3 with the ligand L(1)=4,11-dimethyl-1,8-bis{2-[N-(di-2-pyridylmethyl)amino]ethyl}cyclam were included for comparison purposes. Complex 1 was characterized through elemental analysis, X-ray crystallography, magnetochemistry, electronic spectroscopy, electrochemistry, mass spectrometry and potentiometric titration.

Secondary coordination sphere effects in ruthenium(III) tetraammine complexes: role of the coordinated water molecule.

The complexes trans-[Ru(III)(NH3)4(4-pic)(H2O)](CF3SO3)3 (1) and [Ru(III)(NH3)5(4-pic)](CF3SO3)3 (2) were isolated and studied experimentally by electron paramagnetic resonance (EPR) and UV-vis spectroscopies, cyclic voltammetry, and X-ray crystallography and theoretically by ligand-field theory (LFT) and density functional theory (DFT) calculations. Complex 1 is reported in two different crystal forms, 1a (100 K) and 1b (room temperature). EPR and UV-vis spectroscopies suggest that aqua ligand interaction in this low-spin ruthenium(III) complex changes as a function of hydrogen bonding with solvent molecules.

New La(III) complex immobilized on 3-aminopropyl-functionalized silica as an efficient and reusable catalyst for hydrolysis of phosphate ester bonds.

Described herein is the synthesis, structure, and monoesterase and diesterase activities of a new mononuclear [La(III)(L(1))(NO3)2] (1) complex (H2L(1) = 2-bis[{(2-pyridylmethyl)-aminomethyl}-6-[N-(2-pyridylmethyl) aminomethyl)])-4-methyl-6-formylphenol) in the hydrolysis of 2,4-bis(dinitrophenyl)phosphate (2,4-BDNPP). When covalently linked to 3-aminopropyl-functionalized silica, 1 undergoes disproportionation to form a dinuclear species (APS-1), whose catalytic efficiency is increased when compared to the homogeneous reaction due to second coordination sphere effects which increase the substrate to complex association constant. The anchored catalyst APS-1 can be recovered and reused for subsequent hydrolysis reactions (five times) with only a slight loss in activity.

On the cytotoxic activity of Pd(II) complexes of N,N-disubstituted-N'-acyl thioureas.

The rational design of anticancer drugs is one of the most promising strategies for increasing their cytotoxicity and for minimizing their toxicity. Manipulation of the structure of ligands or of complexes represents a strategy for which is possible to modify the potential mechanism of their action against the cancer cells. Here we present the cytotoxicity of some new palladium complexes and our intention is to show the importance of non-coordinated atoms of the ligands in the cytotoxicity of the complexes.