RESUMO
The X-ray crystal structure and pKa values of GSK322, a well-known and effective peptide deformylase inhibitor and antibacterial drug candidate, are reported. The first examples of Co(iii) complexes of N-formyl hydroxylamines are reported. Reaction of N-hydroxy-N-phenylformamide (HFA) with [Co(tren)Cl2]Cl and [Co(tpa)Cl2]Cl (where tren = tris(2-aminoethyl)amine, tpa = tris(2-pyridylmethyl)amine) with one equivalent of NaOH in H2O afforded [Co(tren)(HFA-1H)](PF6)1.5Cl0.5 (1) and [Co(tpa)(HFA-1H)]Cl2 (2), respectively. X-ray crystal structures of both complexes revealed that the N-formyl hydroxylamine group acts as a bidentate ligand, coordinating the Co(iii) centres via the carbonyl oxygen and deprotonated hydroxy group (O,O'), a coordination mode typically observed for closely related mono-deprotonated hydroxamic acids. Reaction of the N-formyl hydroxylamine-based GSK322 with [Co(tpa)Cl2]Cl afforded the corresponding Co(iii) chaperone complex of the peptide deformylase inhibitor, [Co(tpa)(GSK322-1H)](PF6)2. GSK322 and [Co(tpa)(GSK322-1H)](PF6)2 exhibited better Gram-positive activity than Gram-negative, where low MICs (1.56-6.25 µM) were determined for S. aureus strains, independent of their antibiotic susceptibility.
Assuntos
Amidoidrolases/antagonistas & inibidores , Antibacterianos/farmacologia , Cobalto/farmacologia , Complexos de Coordenação/farmacologia , Inibidores Enzimáticos/farmacologia , Hidroxilaminas/farmacologia , Amidoidrolases/metabolismo , Antibacterianos/síntese química , Antibacterianos/química , Cobalto/química , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Hidroxilaminas/química , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura MolecularRESUMO
: Bismuth compounds have been used extensively as medicines and in particular for the treatment of gastrointestinal ailments. In addition to bismuth's well known gastroprotective effects and efficacy in treating H. pylori infection it also has broad anti-microbial, anti-leishmanial and anti-cancer properties. Aspects of the biological chemistry of bismuth are discussed and biomolecular targets associated with bismuth treatment are highlighted. This review strives to provide the reader with an up to date account of bismuth-based drugs currently used to treat patients and discuss potential medicinal applications of bismuth drugs with reference to recent developments in the literature. Ultimately this review aims to encourage original contributions to this exciting and important field.