Antibacterial activity of metal complexes of antifolate drug pyrimethamine

Ag(I), Co(II) and Cu(II) complexes of pyrimethamine [5-(4- chlorophenyl)-6-ethyl pyrimidinediamine] have been synthesized and characterized by elemental analysis, conductivity measurement, FTIR and UV-Vis spectroscopy. Pyrimethamine act as a monodentate ligand through the pyrimidinic N(1) atom and coordinate the metal ions to give rise to a 4-coordinate tetrahedral and 6-coordinate octahedral for the Co(II) and Cu(II) complexes and linear coordination geometry for the Ag(I) complexes. The in vitro antimicrobial activities of the complexes against some bacteria were determined using the macro dilution method. The Ag(I) complexes showed enhanced activity and their minimum inhibitory concentration and minimum bacteria concentration were determined.Key words: Pyrimethamine, metal complexes, antimicrobial activity, antibiotic, drug resistance

Synthesis, crystal structure, and anticancer studies of organoruthenium(II) p-cymene N-phenyldithiocarbamate complex

Organoruthenium(II) p-cymene N-phenyldithiocarbamate complex, [Ru(phdtc)(η⁶-p-cym)]₂, was synthesized and characterized by elemental analysis, spectroscopic techniques, and single crystal X-ray crystallography. The single crystal X-ray structure of the complex shows that the compound crystallizes in a monoclinic crystal system with a P21/c space group to form a centrosymmetric binuclear complex. The structure consists of two divalent ruthenium(II) ions, two N-phenyldithiocarbamato anions and two p-cymene molecules. Each N-phenyldithiocarbamato anion acts as a chelating ligand to one ruthenium(II) and a bridging ligand to second ruthenium(II) ion in a classic “three-legged piano-stool” arrangement with a pseudo-tetrahedral geometry. The geometry around the ruthenium(II) ions is completed through η6 coordination to the p-cymene carbon atoms. Anticancer studies showed that the compound is potently cytotoxic (complete kill between 10 and 50 μM) when tested up to 100 μM for up to 48 h against two cell lines, HeLa and MRC5-SV2, models of cervical and lung cancer, respectively, and in some instances outperformed the standard platinum-based anticancer drug cisplatin for cytotoxic potency, highlighting the anti-cancer prospect of the complex

Synthesis, characterization and anti-cancer studies of Mn(II), Cu(II), Zn(II) and Pt(II) dithiocarbamate complexes - crystal structures of the Cu(II) and Pt (II) complexes

Mn(II), Cu(II), Zn(II) and Pt(II) complexes of 2-((p-tolylamino)methyl)phenolyldithiocarbamate were synthesized and characterized by elemental analyses and spectroscopic techniques. Spectroscopic studies indicate four coordinate geometry around the metal(II) ions and single crystal X-ray crystallography confirmed the molecular structures of Cu(II) and Pt(II) complexes as distorted square planar. In vitro cytotoxic effects of the complexes, indicative of potential anti-cancer properties, were evaluated using human cancer cell lines HeLa and MRC5-SV2, and a normal cell line, MRC5. The complexes exhibited significant toxicity against the cancer cell lines, with IC50 values of less than 50 µM after 48 h of exposure. Cu(II) and Zn(II) were the most potent and were virtually equipotent in their cytotoxicity against each of the two cancer cells, but only Zn(II) exhibited higher selectivity for a cancer cell than for a normal cell. Mn(II) complex was the least potent, while Pt(II) was the least cancer cell-selective, exhibiting significantly higher toxicity against the parental (normal) MRC-5 cell than against its cancer variant, MRC5-SV2. These compounds could, therefore, inspire the development of inorganic drug leads to generate novel anti-cancer drugs to be delivered directly to the cancerous tissue or through special delivery systems