Heavy Metals as Useful Drugs

A brief overview of the key role for heavy-metal compounds in medicine is given, with a special focus on platinum compounds used in treatment of cancer. Molecular aspects of the mechanism of action are presented in more detail

DNA cleavage and antitumour activity of platinum(II) and copper(II) compounds derived from 4-methyl-2-N-(2-pyridylmethyl)aminophenol: spectroscopic, electrochemical and biological investigation

The reaction of the redox-active ligand, Hpyramol (4-methyl-2-N-(2-pyridylmethyl)aminophenol) with K2PtCl4 yields monofunctional square-planar [Pt(pyrimol)Cl], PtL-Cl, which was structurally characterised by single-crystal X-ray diffraction and NMR spectroscopy. This compound unexpectedly cleaves supercoiled double-stranded DNA stoichiometrically and oxidatively, in a non-specific manner without any external reductant added, under physiological conditions. Spectro-electrochemical investigations of PtL-Cl were carried out in comparison with the analogue CuL-Cl as a reference compound. The results support a phenolate oxidation, generating a phenoxyl radical responsible for the ligand-based DNA cleavage property of the title compounds. Time-dependent in vitro cytotoxicity assays were performed with both PtL-Cl and CuL-Cl in various cancer cell lines. The compound CuL-Cl overcomes cisplatin-resistance in ovarian carcinoma and mouse leukaemia cell lines, with additional activity in some other cells. The platinum analogue, PtL-Cl also inhibits cell-proliferation selectively. Additionally, cellular-uptake studies performed for both compounds in ovarian carcinoma cell lines showed that significant amounts of Pt and Cu were accumulated in the A2780 and A2780R cancer cells. The conformational and structural changes induced by PtL-Cl and CuL-Cl on calf thymus DNA and phi X174 supercoiled phage DNA at ambient conditions were followed by electrophoretic mobility assay and circular dichroism spectroscopy. The compounds induce extensive DNA degradation and unwinding, along with formation of a monoadduct at the DNA minor groove. Thus, hybrid effects of metal-centre variation, multiple DNA-binding modes and ligand-based redox activity towards cancer cell-growth inhibition have been demonstrated. Finally, reactions of PtL-Cl with DNA model bases (9-Ethylguanine and 5'-GMP) followed by NMR and MS showed slow binding at Guanine-N7 and for the double stranded self complimentary oligonucleotide d(GTCGAC)(2) in the minor groove

How to name new chemical elements (IUPAC Recommendations 2016)

A procedure is proposed to name new chemical elements. After the discovery of a new element is established by the joint IUPAC-IUPAP Working Group, the discoverers are invited to propose a name and a symbol to the IUPAC Inorganic Chemistry Division. Elements can be named after a mythological concept, a mineral, a place or country, a property or a scientist. After examination and acceptance by the Inorganic Chemistry Division, the proposal follows the accepted IUPAC procedure and is then ratified by the Council of IUPAC. This document is a slightly amended version of the 2002 IUPAC Recommendations; the most important change is that the names of all new elements should have an ending that reflects and maintains historical and chemical consistency. This would be in general “-ium” for elements belonging to groups 1–16, i.e. including the f-block elements, “-ine” for elements of group 17 and “-on” for elements of group 18.This manuscript (PAC-REP-15-08-02) was prepared in the framework of IUPAC project 2015-031-1-200

A phosphorus NMR study of the reaction products of cis-diamminedichloroplatinum (II) with a double-helical oligonucleotide and with DNA

AbstractThe structural distortion of oligonucleotides upon cis-PtCl2(NH3)2{d(T-C-T-C-G-G-T-C-T'-C-N7(5) N7(6)} reveals shifting of 4 phosphorus resonances due to platination. 3 Resonances could be assigned by selective 31P-irradiation, showing P(6) (P between the two Gs) to be shifted 1.5 ppm to low field. In the concomitant double strands P(6) is shifted 0.9 ppm to lower field. A similar peak has been observed in platinated salmon sperm DNA (37°C), indicating that Pt-binding to GpG-fragments in DNA is similar to that found for the decanucleotide, so the distortion of DNA might be comparable

Tetrahedral zinc in tetrakis(1-methyl-1H-imidazole-kappa N-3)zinc bis(tetrafluoridoborate)

Peer reviewe

Bis{μ-2-[(4,6-bis{(2-hydroxy-5-methylphenyl)[(pyridin-2-yl)methyl]amino}-1,3,5-triazin-2-yl)[(pyridin-2-yl-κN)methyl]amino-κN]-4-methyl­phenolato-1:2κ2 O:O}bis­[(nitrato-κ2 O,O′)zinc]–acetonitrile–water (2/4/1)

The title compound, [Zn2(C42H38N9O3)2(NO3)2]·2CH3CN·0.5H2O, is a bis-phenolate-bridged dinuclear ZnII complex. The asymmetric unit comprises half the zinc complex (the full complex is completed by the application of a centre of inversion), one acetonitrile solvent mol­ecule and a quarter of a water mol­ecule (located on a twofold axis with half-occupancy; H atoms were not located for this mol­ecule). Each triazine-based multidentate ligand uses a phenolate group to bridge ZnII ions, generating a Zn2O2 core. The ZnII ions are five-coordinate, with an additional long Zn—O contact [2.6465 (16) Å], and include a semi-bidentate nitrate ion and a N,N′,O-tridentate mode of the ligand in the coordination sphere. Non-coordinating pyridine groups form intra­molecular O—H⋯N hydrogen bonds with phenol groups. As suggested by the short O⋯O donor–acceptor distances between the disordered water molecules and phenol O atoms, these groups also participate in hydrogen bonding