Ruthenium polypyridyl complexes and their modes of interaction with DNA : is there a correlation between these interactions and the antitumor activity of the compounds?

Various interaction modes between a group of six ruthenium polypyridyl complexes and DNA have been studied using a number of spectroscopic techniques. Five mononuclear species were selected with formula [Ru(tpy) L1L2](2-n)?, and one closely related dinuclear cation of formula [{Ru(apy)(tpy)}2{l-H2N(CH2)6NH2}]4?. The ligand tpy is 2,20:60,200-terpyridine and the ligand L1 is a bidentate ligand, namely, apy (2,20-azobispyridine), 2-phenylazopyridine, or 2-phenylpyridinylmethylene amine. The ligand L2 is a labile monodentate ligand, being Cl-, H2O, or CH3CN. All six species containing a labile L2 were found to be able to coordinate to the DNA model base 9-ethylguanine by 1H NMR and mass spectrometry. The dinuclear cationic species, which has no positions available for coordination to a DNA base, was studied for comparison purposes. The interactions between a selection of four representative complexes and calf-thymus DNA were studied by circular and linear dichroism. To explore a possible relation between DNA-binding ability and toxicity, all compounds were screened for anticancer activity in a variety of cancer cell lines, showing in some cases an activity which is comparable to that of cisplatin. Comparison of the details of the compound structures, their DNA binding, and their toxicity allows the exploration of structure–activity relationships that might be used to guide optimization of the activity of agents of this class of compounds

Designing organometallic compounds for catalysis and therapy

Bioorganometallic chemistry is a rapidly developing area of research. In recent years organometallic compounds have provided a rich platform for the design of effective catalysts, e.g. for olefin metathesis and transfer hydrogenation. Electronic and steric effects are used to control both the thermodynamics and kinetics of ligand substitution and redox reactions of metal ions, especially Ru II. Can similar features be incorporated into the design of targeted organometallic drugs? Such complexes offer potential for novel mechanisms of drug action through incorporation of outer-sphere recognition of targets and controlled activation features based on ligand substitution as well as metal- and ligand-based redox processes. We focus here on η 6-arene, η 5-cyclopentadienyl sandwich and half-sandwich complexes of Fe II, Ru II, Os II and Ir III with promising activity towards cancer, malaria, and other conditions. © 2012 The Royal Society of Chemistry

Editorial: The Golden Future in Medicinal Chemistry: Perspectives and Resources From Old and New Gold-Based Drug Candidates

This editorial summarizes the content of the scientific contributions received for the research topic entitled "The Golden Future in Medicinal Chemistry: Perspectives and Resources From Old and New Gold-Based Drug Candidates" and published in Frontiers in Chemistry

Synthesis, structural and spectroscopic characterization, in vitro cytotoxicity and in vivo activity as free radical scavengers of chlorido(p-cymene) complexes of ruthenium(II) containing N-alkylphenothiazines

Three new ruthenium(II) complexes 1-3 containing N-alkylphenothiazine molecules were synthesized by reaction of [RuCl2(eta(6)-P-cymene)](2) with chlorpromazine hydrochloride (1), trifluoperazine dihydrochloride (2) or thioridazine hydrochloride (3). The compounds of the general formula L[RuCl3(eta(6)-p-cymene)] were characterized by elemental analysis and spectroscopic methods (FT-IR, UV-Vis, H-1 and C-13 NMR). Complex 2 was structurally characterized by single crystal X-ray diffraction. In vitro cytotoxic activity of complexes 1-3 were assayed in four human carcinoma cell lines MCF-7, MDA-MB-453 (breast carcinoma), SW-480 (colon carcinoma) and IM9 (myeloma multiple cells). The highest cytotoxicity (12.1 lt = IC50 lt = 17.3 mu M) and induced a total (SW-480) or almost total cell death (MCF-7. MDA-MB-453) at 25 mu M in 48 h of treatment were observed for complex 2. The influence of three different doses (0.4, 4.5 and 90.4 mu M/kg bw) of complex 2 on activities of antioxidants enzymes (superoxide dismutase (SOD) and catalase (CAT)) and lactate dehydrogenase (LDH) were investigated under physiological conditions. The effects on nitrite production (NO2-) and level of erythrocytes malondialdehyde (MDA) in rats blood were evaluated, too. (C) 2011 Elsevier Masson SAS. All rights reserved

New ruthenium(II) complexes with N-alkylphenothiazines: Synthesis, structure, in vivo activity as free radical scavengers and in vitro cytotoxicity

Three new complexes of the general formula L[RuCl(3)(DMSO)(3)] (1-3), where L = chlorpromazine hydrochloride, trifluoroperazine dihydrochloride or thioridazine hydrochloride, were prepared and characterized by elemental analysis and spectroscopic methods (FT-IR, UV-Vis, (1)H NMR and (13)C NMR). In addition, the crystal structure of the complex 2 containing trifluoroperazine dihydrochloride was solved by single crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group P2(1)/n, with a = 10.4935(7) angstrom, b = 18.6836(12) angstrom, c = 19.9250(13) angstrom, beta = 98.448(2)degrees, V = 3864.0(4) angstrom(3). The structure was refined to the agreement factors of R = 4.79%, R(w) = 11.23%. The effect of three different doses (0.4, 4.5 and 90.4 mu M/kg bw) of complex 2 on superoxide dismutase (SOD) and catalase (CAT) activity was investigated under physiological conditions. Influence on nitrite production (NO(2)(-)) and the level of erythrocytes malondialdehyde (MDA) in rats blood was also evaluated. Complex 2 did not affect the CAT enzyme activity in vivo and did not cause the hydroxyl radicals production. In the 0.4 and 4.5 mu M/kg bw doses it showed almost the same or lower SOD activity and nitrite levels, while the dose of 90.4 mu M/kg bw significantly increased these parameters. Finally, the cytotoxicity of complexes were assayed in four human carcinoma cell lines MCF-7, MDA-MB-453 (breast carcinoma), SW-480 (colon adenocarcinoma) and IM9 (myeloma multiple cells). Antiproliferative activity in vitro with low IC(50) during 48 h of treatment was observed. (C) 2010 Elsevier Masson SAS. All rights reserved

Synthesis, structural characterization and cytotoxic activity of two new organoruthenium(II) complexes

Two new p-cymene ruthenium(II) complexes containing as additional ligands N-methylpiperazine ([(η6-p-cymene)RuCl2(CH3NH(CH2)4NH)]PF6, complex 1) or vitamin K3-thiosemicarbazone ([(η6-p-cymene)RuCl2(K3tsc)], complex 2) were synthesized starting from [(η6-p-cymene)2RuCl2]2 and the corresponding ligand. The complexes were characterized by elemental analysis, IR, electronic absorption and NMR spectroscopy. The X-ray crystal structure determination of complex 1 revealed “piano-stool” geometry. The differences in the cytotoxic activity of the two complexes are discussed in terms of the ligand present