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Two ruthenium(III) complexes bearing the thiazole ligand, namely, thiazolium tetrachlororuthenate (TzICR) thiazolium tetrachlororuthenate (TzNAMl) were prepared and characterized. The crystal structures of both complexes were solved by x-ray diffraction methods and found to match closely those of the corresponding imidazole complexes.

Keppler-type ruthenium(III) complexes exhibit promising antitumor properties. A study of 2-aminothiazolium[trans-tetrachlorobis(2-aminothiazole)ruthenate(III)], both in the solid state and in solution is reported.

A structural characterization of the zinc(II) and copper(II) complexes of clioquinol is reported. A ligand to metal stoichiometry of 2:1 is found in both cases, though in the presence of quite different coordination polyhedra, the findings are discussed in the frame of modern approaches to AlzheimerEs disease treatment.

Research has been conducted on L-ascorbic acid. Results demonstrate that the slow decomposition of this acid carried out under aerobic pressure in the presence of cadmium ions has led to a crystalline product which is insoluble in water.

The studies on the reaction of bovine serum albumin (BSA) with [trans-Ru[Cl.sub.4](Im)(dimethylsulfoxide)][ImH] (Im = imidazole) (NAMI-A), an experimental ruthenium(III) anticancer drug and the formation of the respective NAMI-A/BSA adduct are presented. The results confirmed X-ray absorption spectroscopy to be a very suitable method for the characterization of metallodrug/protein adduct and nature and mechanism of its formation.

A series of structurally related oxo-bridged binuclear gold(III) complexes are analyzed by using density functional theory (DFT) calculations. The studies have shown that the compound has the most pronounced oxidizing character and has displayed the greatest reactivity with model proteins and the largest cytotoxic effects.

An efficient one-step synthesis of fac-[Ru[(CO).sub.3][Cl.sub.2](THZ)] (THZ = 1,3-thiazole) from commercial [[Ru[(CO).sub.3][Cl.sub.2]].sub.2] is described. The reactivity of fac-[Ru[(CO).sub.3]C[l.sub.2](THZ)] with biomolecules and synthetic hydrogels makes it a compound of interest for anticancer and antimetastases tests.

Research has been conducted on ruthenium-thiopyrimidine complexes. The authors discuss the crystal and molecular structures of these complexes, the molecular modeling analysis of the molecules, and the spectrophotometric, redox and cytoxic properties of these molecules.

A novel dinuclear platinum(II) complex, showing innovative structural features has been prepared and characterized by X-ray diffraction. This dinuclear platinum complex exhibits significant growth-inhibiting properties on a panel of cultured human tumor cell lines.

Research has been conducted on terbium(III) complex with quinizarine 2-sulfonate. The study of the crystal structure of the complex has been carried out via the use of single-crystal X-ray diffraction methods, and the details are reported.

Six diiodido-diamine platinum(II) complexes, either cis or trans configured, were prepared, differing only in the nature of the amine ligand (isopropylamine, dimethylamine, or methylamine), and their antiproliferative properties were evaluated against a panel of human tumor cell lines. Both series of complexes manifested pronounced cytotoxic effects, with the trans isomers being, generally, more effective than their cis counterparts. Cell cycle analysis revealed different modes of action for these new Pt(II) complexes with respect to cisplatin. The reactivity of these platinum compounds with a number of biomolecules, including cytochrome c, two sulfur containing modified amino acids, 9-ethylguanine, and a single strand oligonucleotide, was analyzed in depth by mass spectrometry and NMR spectroscopy. Interestingly, significant differences in the reactivity of the investigated compounds toward the various model biomolecules were observed: in particular we observed that trans complexes preferentially release their iodide ligands upon biomolecule binding, while the cis isomers may release the amine ligands with retention of iodides. Such differences in reactivity may have important mechanistic implications and a relevant impact on the respective pharmacological profiles. [ABSTRACT FROM AUTHOR]

The reaction of bovine serum albumin (BSA) with [trans-RuCI4(lm)(dimethylsulfoxide)][ImH] (Im = imidazole) (NAMI-A), an experimental ruthenium(lll) anticancer drug, and the formation of the respective NAMI-NBSA adduct were investigated by X-ray absorption spectroscopy (XAS) at the sulfur and chlorine K-edges and at the ruthenium K- and L3-edges. Ruthenium K and L3-edge spectra proved unambiguously that the ruthenium center remains in the oxidation state +3 after protein binding. Comparative analysis of the chlorine K-edge XAS spectra of NAMI-A and NAMI-NBSA, revealed that the chlorine environment is greatly perturbed upon protein binding. Only modest changes were observed in the sulfur K-edge spectra that are dominated by several protein sulfur groups. Overall, valuable information on the nature of this metallodrug/protein adduct and on the mechanism of its formation was gained; XAS spectroscopy turns out to be a very suitable method for the characterization of this kind of systems. [ABSTRACT FROM AUTHOR]

The reactivity of cis-diamminediiodidoplatinum(II), cis-PtI2(NH3)2, the iodo analogue of cisplatin, with hen egg white lysozyme (HEWL) was investigated by electrospray ionization mass spectrometry and X-ray crystallography. Interestingly, the study compound forms a stable 1:1 protein adduct for which the crystal structure was solved at 1.99 Å resolution. In this adduct, the PtII center, upon release of one ammonia ligand, selectively coordinates to the imidazole of His15. Both iodide ligands remain bound to platinum, with this being a highly peculiar and unexpected feature. Notably, two equivalent modes of PtII binding are possible that differ only in the location of I atoms with respect to ND1 of His15. The structure of the adduct was compared with that of HEWL-cisplatin, previously described; differences are stressed and their important mechanistic implications discussed. [ABSTRACT FROM AUTHOR]

Two ruthenium(III) complexes bearing the thiazole ligand, namely, thiazolium (bisthiazole) tetrachlororuthenate (I, TzlCR) and thiazolium (thiazole, DMSO) tetrachlororuthenate (II, TzNAMI) were prepared and characterized. The crystal structures of both complexes were solved by X-ray diffraction methods and found to match closely those of the corresponding imidazole complexes. The behavior in aqueous solution of bothTzlCR and TzNAMI was analyzed spectroscopically. The time-dependent spectrophotometric profiles resemble closely those of the related ICR and NAMI-A anticancer compounds, respectively. It is observed that replacement of imidazole with thiazole, a less basic ligand, produces a significant decrease of the ligand exchange rates in the case of the NAMI-like compound. The main electrochemical features of these ruthenium(III) thiazole complexes were determined and compared to those of ICR and NAMI-A. Moreover, some preliminary data were obtained on their biological properties. Notably, both complexes exhibit higher reactivity toward serum albumin than toward calf thymus DNA; cytotoxicity is negligible in line with expectations. A more extensive characterization of the pharmacological properties in vivo is presently in progress. [ABSTRACT FROM AUTHOR]

The reactions of human β-amyloid peptide 1-28 (Aβ28) with Al(III) and Fe(III) ions were investigated by (1)H NMR and electrospray ionization mass spectrometry (ESI-MS) under pH conditions close to physiological ones. (1)H NMR titrations, performed in the 5.3-8.0 pH range, revealed that no measurable amounts of Aβ28-Al(III) or Aβ28-Fe(III) adducts are formed; such metal adducts could not be obtained even by changing a number of experimental conditions, e.g., temperature, buffer, nature of the salt, etc. These observations were later confirmed by ESI-MS. It is thus demonstrated that Aβ28, at physiological pH, is not able to form binary complexes with Al(III) and Fe(III) ions of sufficient stability to compete with metal hydroxide precipitation. The biological implications of these findings are discussed in the frame of current literature., (© 2011 American Chemical Society)

The reaction of the ruthenium(II) complex fac-[Ru(CO)(3)Cl(2)(N(1)-thz)] (I hereafter; thz = 1,3-thiazole) with human beta-amyloid peptide 1-28 (Abeta(28)) and the resulting {Ru(CO)(3)}(2+) peptide adduct was investigated by a variety of biophysical methods. (1)H NMR titrations highlighted a selective interaction of {Ru(CO)(3)}(2+) with Abeta(28) histidine residues; circular dichroism revealed the occurrence of a substantial conformational rearrangement of Abeta(28); electrospray ionization mass spectrometry (ESI-MS) suggested a prevalent 1:1 metal/peptide stoichiometry and disclosed the nature of peptide-bound metallic fragments. Notably, very similar ESI-MS results were obtained when I was reacted with Abeta(42). The implications of the above findings for a possible use of ruthenium compounds in Alzheimer's disease are discussed.