RESUMO
The Cambridge Structural Database was evaluated for crystals containing Se O chalcogen bonding interactions. These secondary bonding interactions are found to operate independently of complementary intermolecular interactions in about 13% of the structures they can potentially form. This number rises significantly when more specific interactions are considered, e.g. Se O(carbonyl) interactions occur in 50% of cases where they can potentially form. In about 55% of cases, the supramolecular assemblies sustained by Se O(oxygen) interactions are one-dimensional architectures, with the next most prominent being zero-dimensional assemblies, at 30%.
RESUMO
Four binuclear phosphanesilver(I) dithiocarbamates, {cyclohexyl3PAg(S2CNRR')}2 for Râ¯=â¯R'â¯=â¯Et (1), CH2CH2 (2), CH2CH2OH (3) and Râ¯=â¯Me, R'â¯=â¯CH2CH2OH (4) have been synthesised and characterised by spectroscopy and crystallography, and feature tri-connective, µ2-bridging dithiocarbamate ligands and distorted tetrahedral geometries based on PS3 donor sets. The compounds were evaluated for anti-bacterial activity against a total of 12 clinically important pathogens. Based on minimum inhibitory concentration (MIC) and cell viability tests (human embryonic kidney cells, HEK 293), 1-4 are specifically active against Gram-positive bacteria while demonstrating low toxicity; 3 and 4 are active against methicillin resistant S. aureus (MRSA). Across the series, 4 was most effective and was more active than the standard anti-biotic chloramphenicol. Time kill assays reveal 1-4 to exhibit both time- and concentration-dependent pharmacokinetics against susceptible bacteria. Compound 4 demonstrates rapid (within 2â¯h) bactericidal activity at 1 and 2â¯×â¯MIC to reach a maximum decrease of 5.2â¯log10â¯CFU/mL against S. aureus (MRSA).
Assuntos
Antibacterianos , Complexos de Coordenação , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Prata , Tiocarbamatos , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Cloranfenicol/farmacologia , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Avaliação Pré-Clínica de Medicamentos , Prata/química , Prata/farmacologia , Tiocarbamatos/síntese química , Tiocarbamatos/química , Tiocarbamatos/farmacologiaRESUMO
Despite being disparaged for their malodorous and toxic demeanour, compounds of selenium, a bio-essential element, and tellurium, offer possibilities as therapeutic agents. Herein, their potential use as drugs, for example, as anti-viral, anti-microbial, anti-inflammatory agents, etc., will be surveyed along with a summary of the established biological functions of selenium. The natural biological functions of tellurium remain to be discovered.
Assuntos
Descoberta de Drogas/métodos , Compostos Organometálicos/química , Compostos Organometálicos/uso terapêutico , Compostos de Selênio/química , Compostos de Selênio/uso terapêutico , Selênio/química , Telúrio/química , HumanosRESUMO
The cytotoxicity and anti-tumour activity screening trials for both gold(I) and gold(III) are summarised. Gold(I) thiolates employed clinically in the treatment of rheumatoid arthritis display some potency against various tumours but a greater potential is found in their analogues. In particular, analogues featuring a linear P-Au-S arrangement in which the thiolate ligand is derived from a biologically active thiol display high potency. Further, targeting mitochondria with tetrahedrally coordinated gold(I) phosphine compounds with enhanced hydrophilicity is a research direction with exciting potential. Recent research has shown that gold(III) compounds featuring square-planar geometries, as found in cisplatin, may target DNA and may provide new anti-tumour agents.