RESUMO
Thymidylate kinase (TMK) is an essential enzyme in bacterial DNA synthesis. The deoxythymidine monophosphate (dTMP) substrate binding pocket was targeted in a rational-design, structure-supported effort, yielding a unique series of antibacterial agents showing a novel, induced-fit binding mode. Lead optimization, aided by X-ray crystallography, led to picomolar inhibitors of both Streptococcus pneumoniae and Staphylococcus aureus TMK. MICs < 1 µg/mL were achieved against methicillin-resistant S. aureus (MRSA), S. pneumoniae, and vancomycin-resistant Enterococcus (VRE). Log D adjustments yielded single diastereomers 14 (TK-666) and 46, showing a broad antibacterial spectrum against Gram-positive bacteria and excellent selectivity against the human thymidylate kinase ortholog.
Assuntos
Antibacterianos/farmacologia , Benzoatos/farmacologia , Enterococcus/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Núcleosídeo-Fosfato Quinase/antagonistas & inibidores , Staphylococcus aureus/efeitos dos fármacos , Streptococcus pneumoniae/efeitos dos fármacos , Timina/análogos & derivados , Resistência a Vancomicina/efeitos dos fármacos , Antibacterianos/síntese química , Benzoatos/síntese química , Domínio Catalítico , Cristalografia por Raios X , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Núcleosídeo-Fosfato Quinase/metabolismo , Relação Estrutura-Atividade , Timina/síntese química , Timina/farmacologiaRESUMO
Trimethyl (3R)-homocitrate 17, trimethyl (2S,3R)-[2-2H1]-homocitrate 17a and (2R,3R)-[2-2H1]-homocitrate 17b, as well as dimethyl (3R)-homocitrate lactone 18, (2S,3R)-[2-2H1]-homocitric lactone 18a and (2R,3R)-[2-2H1]-homocitric lactone 18b have been synthesised. D-quinic acid 12 was used as the source of the (3R)-centre in the unlabelled target compounds 17 and 18. (2)-Shikimic acid 19 and the (2)-[2-2H]-shikimic acid derivative 32 respectively were used in the synthesis of the labelled compounds. In the latter syntheses, Sharpless directed epoxidation of the olefin in the 5-deoxy ester diols 23 and 35 ensured a reaction from the same face as the allylic and homoallylic alcohols, and the reduction of the protected epoxides 25 and 37 ensured that the label was introduced in a stereoselective manner. The 1H NMR spectra of the labelled products present an assay for the stereochemistry of the biological reactions catalysed by homocitrate synthase and by the protein from the nifV gene.
Assuntos
Proteínas de Bactérias/metabolismo , Lactonas/síntese química , Lactonas/metabolismo , Oxo-Ácido-Liases/metabolismo , Ácidos Tricarboxílicos/síntese química , Ácidos Tricarboxílicos/metabolismo , Catálise , Lactonas/química , Lisina/metabolismo , Espectroscopia de Ressonância Magnética , Metilação , Estrutura Molecular , Estereoisomerismo , Ácidos Tricarboxílicos/químicaRESUMO
A series of novel pyridazine analogues were prepared and the structure-activity relationship of their behavior as inhibitors of PTP1B was evaluated. Most of the analogues had potencies in the low micromolar range. The in vitro kinetics of this compound series demonstrated that they were reversible non-competitive binders. This indicates that there may exist another site in the enzyme through which enzyme activity can be inhibited, which is not a recognized interaction domain. Some of the analogues exhibited high selectivity for other PTPases, for example, compound 12 mp showed 20-fold selectivity for PTP1B (IC50=5.6 microM) versus both TCPTP and LAR (>100 microM, respectively). In contrast to many tyrosine phosphatase mimetic inhibitors, this compound class lacks negative charge and thus showed high permeability across cell membranes. Selective analogues in the series were analyzed in an in vitro cellular assay, which showed increased insulin-stimulated insulin receptor phosphorylation.