Search

The reaction of [Ru2(CO)6Cl4], 1, with excess THZ (1,3-thiazole) in absolute ethanol at 55 degrees C produces fac-[Ru(CO)3Cl2(THZ)], 2, in high yield. [Ru(CO)2Cl2(THZ)2], 3, is formed at higher temperature (ca 70 degrees C) and higher concentration of THZ. The X-ray structures of the new compounds have been determined, and density functional studies performed at the hybrid B3LYP/(Lanl2DZ, Ru; 6-311+G**, CHClNOS) level allowed the estimation of the structures of several conformers as well as that of their relative total electronic energies. Compound 2 is soluble (slowly) in aqueous media, where it reacts with the transport proteins bovine serum albumin (BSA) and human apotransferrin (HTF), and at a lower extent with calf thymus DNA (CT-DNA) and with guanosine-5'-monophosphate (GMP). The complex molecule is adsorbed by certain synthetic acryloyl polymers that have terminal carboxylate functions and is embedded in silica gels when these latter are prepared in the presence of a solution of 2. Ruthenium species are slowly released from the loaded gels into physiological solutions at pH 7.4. The reactivity of 2 with biomolecules and synthetic hydrogels makes it a compound of interest for anticancer and antimetastases tests.

The synthesis and characterization of the silver(I) chloride complex of formula {[AgCI(CMBZT)(TPTP) 2]·(MeOH)} (1) (CMBZT = 5-chloro-2-mercaptobenzothiazole, TPTP = tris(p-tolyl)phosphine) is described. Also the structure of the hydrate derivative {[AgCI(TPTP) 3]·(0.5·H2O)} (2) of the corresponding known anhydrous silver complex (Zartilas et al., 2009), and the polymorph 3 of the known [AgI(TPTP) 3] complex (Zartilas et al., 2009) were determined and compared with the known ones. In addition, the structure of the known one silver(I) cluster {[AgI(TPTP)] 4} (4) (Meijboom et al., 2009) was re-determined at 120(2) K and possible Ag-Ag interactions were analyzed. The compounds 1-4 were characterized by X-ray crystallography at r.t (1) and 120 K (2-4). All these complexes and {[(Et3NH+)]2 · [Ag6 (µ3-Hmna) 4(µ3-mna) 2]2- · (DMSO) 2 · (H2O)} (5) (Hmna = 2- mercaptonicotinic acid) were evaluated for cytotoxic and anti-inflammatory activity. The in vitro testing of cytotoxic activity of 1--5 against leiomyosarcoma cancer cells (LMS), were evaluated with Trypan Blue and Thiazolyl Blue Tetrazolium Bromide or 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazoliumbromide (MTT) assays. The flow cytometry assay for complex 1 and showed that at 15 µM of 1, 62.38% of LMS cells undergo apoptosis, while 7% of LMS cells undergo cell necrosis. The antitumor activity of 3 is comparable with that of its reported polymorph (Zartilas et al., 2009). The anti-inflammatory, activity of complexes 1-3 and 5 was also studied. The activity towards cell viability was 2 > 3 > 5 > 1 > 4, while the order of the inhibitory activity in cell growth proliferation follows the order, 2 > 3 > 1 > 4 > 5. The anti-inflammatory activity on the other hand is 1 > 2 > 5 > … > 3. [ABSTRACT FROM AUTHOR]

The reactions of tetrachloroauric(III) acid (HAuCl4) with the thioamides; 2-mercapto-benzothiazole (mbztH) and 5-ethoxy-2-mercapto-benzimidazole (EtmbzimH) lead to the desulfuration of the ligands and the formation of the ionic complexes {[AuCl4]−[bztH2]+} (1), and {[AuCl4]−[EtbzimH2]+(H2O)} (2) (where bztH2+and EtbzimH2+are the desulfurated cations of the starting ligands). The reaction of HAuCl4with 2-mercapto-nicotinic acid (mnaH2), however results in the formation of 2-sulfonate-nicotininc acid (C6H5NO5S) (3) with the simultaneous oxidation of the sulfur atom. On the other hand, the reactions of the gold(I) complex [Au(tpp)Cl] (4) (tpp = triphenylphosphine (Ph3P)) with the thioamides; 2-mercapto-thiazolidine (mtzdH), 2-mercapto-benzothiazole (mbztH) and 5-chloro-2-mercapto-benzothiazole (ClmbztH) in the presence of potassium hydroxide resulted in the formation of the gold(I) complexes of formulae [Au(tpp)(mtzd)] (5), [Au(tpp)(mbzt)] (6) and [Au(tpp)(Clmbzt)] (7) without ligand desulfuration. All complexes have been characterized by elemental analysis, FT-IR, far-FT-IR,1H-NMR, spectroscopic techniques and X-Ray crystallography. The electrochemical behavior of 1, 2and 4-7complexes and the ligands EtmbzimH, mbztH and mnaH2was also studied in acetonitrile and DMF using cyclic voltammetry. The results are in support of a mechanism of desulfuration of the ligands by Au(III), involving a first oxidation of S to -SO3−, followed by a C-S bond cleavage. This is also supported by PM6 calculations of bond dissociation energies of the various compounds involved. Complexes 1, 2and 4-7were tested for in vitrocytotoxicity against leiomyosarcoma cells and the results are discussed in relation with the geometry of the complexes and compared with those of cisplatin and other metals. Complexes 1and 5showed higher activity than that of cisplatin, while HAuCl4was inactive against sarcoma cells. [ABSTRACT FROM AUTHOR]