RESUMO
The stress-activated kinase p38α was used to evaluate a fragment-based drug discovery approach using the BioFocus fragment library. Compounds were screened by surface plasmon resonance (SPR) on a Biacore(™) T100 against p38α and two selectivity targets. A sub-set of our library was the focus of detailed follow-up analyses that included hit confirmation, affinity determination on 24 confirmed, selective hits and competition assays of these hits with respect to a known ATP binding site inhibitor. In addition, functional activity against p38α was assessed in a biochemical assay using a mobility shift platform (LC3000, Caliper LifeSciences). A selection of fragments was also evaluated using fluorescence lifetime (FLEXYTE(™)) and microscale thermophoresis (Nanotemper) technologies. A good correlation between the data for the different assays was found. Crystal structures were solved for four of the small molecules complexed to p38α. Interestingly, as determined both by X-ray analysis and SPR competition experiments, three of the complexes involved the fragment at the ATP binding site, while the fourth compound bound in a distal site that may offer potential as a novel drug target site. A first round of optimization around the remotely bound fragment has led to the identification of a series of triazole-containing compounds. This approach could form the basis for developing novel and active p38α inhibitors. More broadly, it illustrates the power of combining a range of biophysical and biochemical techniques to the discovery of fragments that facilitate the development of novel modulators of kinase and other drug targets.
Assuntos
Descoberta de Drogas/métodos , Proteína Quinase 14 Ativada por Mitógeno/química , Bibliotecas de Moléculas Pequenas/química , Triazóis/química , Sítios de Ligação , Compostos Bicíclicos com Pontes/química , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Ligantes , Conformação Molecular , Fragmentos de Peptídeos/química , Ligação Proteica , Ressonância de Plasmônio de Superfície/métodos , Difração de Raios XRESUMO
Bioisosteric replacement of piperazine with an aryl ring in lead VR1 antagonist 1 led to the biarylamide series. The development of B-ring SAR led to the conformationally constrained analog 70. The resulting aminoquinazoline 70 represents a novel VR1 antagonist with improved in vitro potency and oral bioavailability vs the analogous compounds from the lead series.
Assuntos
Amidas/farmacologia , Analgésicos não Narcóticos/síntese química , Canais de Cátion TRPV/antagonistas & inibidores , Administração Oral , Amidas/síntese química , Amidas/farmacocinética , Analgésicos não Narcóticos/farmacocinética , Animais , Disponibilidade Biológica , Humanos , Conformação Molecular , Dor/tratamento farmacológico , Quinazolinas/síntese química , Quinazolinas/farmacologia , Ratos , Solubilidade , Relação Estrutura-Atividade , Ureia/análogos & derivados , Ureia/síntese química , Ureia/farmacologiaRESUMO
2,5-Dihydropyrazolo[4,3-c]pyridin-3-ones are GABAA receptor benzodiazepine binding site ligands with functional selectivity for the alpha3 subtype over the alpha1 subtype. SAR studies to optimise this functional selectivity are described.
Assuntos
Pirazóis/síntese química , Receptores de GABA-A/metabolismo , Animais , Benzodiazepinas/química , Benzodiazepinas/metabolismo , Sítios de Ligação , Humanos , Cinética , Ligantes , Estrutura Molecular , Técnicas de Patch-Clamp , Pirazóis/farmacologia , Piridinas/química , Piridinas/metabolismo , Ensaio Radioligante , Relação Estrutura-AtividadeRESUMO
On the basis of a spirocyclic ether screening lead, a series of acyclic sulfones have been identified as high-affinity, selective 5-HT(2A) receptor antagonists. Bioavailability lacking in the parent, 1-(2-(2,4-difluorophenyl)ethyl)-4-(phenylsulfonyl)piperidine (12), was introduced by using stability toward rat liver microsomes as a predictor of bioavailability. By this means, the 4-cyano- and 4-carboxamidophenylsulfonyl derivatives 26 and 31 were identified as orally bioavailable, brain-penetrant analogues suitable for evaluation in animal models. Bioavailability was also attainable by N substitution leading to the N-phenacyl derivative 35. IKr activity detected through counterscreening was reduced to insignificant levels in vivo with the latter compound.