RESUMO
A screening of compound libraries based on nipecotic acid derivatives with lipophilic residues attached to the scarcely explored 5-position of the core structure was used for the search of new inhibitors of the γ-aminobutyric acid (GABA) transporterâ 1 (mGAT1). The generated compound libraries, which were based on hydrazone chemistry commonly used in dynamic combinatorial chemistry but rendered pseudostatic, were screened for their binding affinities toward mGAT1 by means of MS Binding Assays. With nipecotic acid derived hydrazone rac-16 h [rac-(3R,5S)-{5-[(E)-2-{[5-(2-phenylethynyl)thiophen-2-yl]methylidene}hydrazin-1-yl]piperidine-3-carboxylic acid}-sodium chloride (1/2)], one hit was found and evaluated displaying sub-micromolar potency (pKi =6.62±0.04) and a noncompetitive interaction mode at mGAT1. By bearing a 5-(2-phenylethynyl)thiophen-2-yl residue attached to the 5-position of nipecotic acid via a three-atom spacer, compound rac-16 h contains a structural moiety so far unprecedented for these kinds of bioactive molecules, and complements novel 5-substituted nipecotic acid derived ligands of mGAT1 revealed in a recently published screening campaign. This new class of ligands, with an inhibition mode distinct from that of benchmark mGAT1 inhibitors, could serve as research tools for investigations of mGAT1-mediated GABA transport.
Assuntos
Proteínas da Membrana Plasmática de Transporte de GABA/metabolismo , Inibidores da Captação de GABA/química , Hidrazonas/química , Ácidos Nipecóticos/química , Bibliotecas de Moléculas Pequenas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Ligação Competitiva , Cromatografia Líquida de Alta Pressão , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores da Captação de GABA/metabolismo , Células HEK293 , Humanos , Hidrazonas/metabolismo , Ligantes , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/metabolismo , Relação Estrutura-AtividadeRESUMO
Inducible Hsp70 (Hsp70i) is overexpressed in a wide spectrum of human tumors, and its expression correlates with metastasis, poor outcomes, and resistance to chemotherapy in patients. Identification of small-molecule inhibitors selective for Hsp70i could provide new therapeutic tools for cancer treatment. In this work, we used fluorescence-linked enzyme chemoproteomic strategy (FLECS) to identify HS-72, an allosteric inhibitor selective for Hsp70i. HS-72 displays the hallmarks of Hsp70 inhibition in cells, promoting substrate protein degradation and growth inhibition. Importantly, HS-72 is selective for Hsp70i over the closely related constitutively active Hsc70. Studies with purified protein show HS-72 acts as an allosteric inhibitor, reducing ATP affinity. In vivo HS-72 is well-tolerated, showing bioavailability and efficacy, inhibiting tumor growth and promoting survival in a HER2+ model of breast cancer. The HS-72 scaffold is amenable to resynthesis and iteration, suggesting an ideal starting point for a new generation of anticancer therapeutics targeting Hsp70i.
Assuntos
Benzimidazóis/química , Benzimidazóis/farmacologia , Proteínas de Choque Térmico HSP70/antagonistas & inibidores , Proteínas de Choque Térmico HSP70/metabolismo , Ácidos Nipecóticos/química , Ácidos Nipecóticos/farmacologia , Piperidinas/química , Piperidinas/farmacologia , Regulação Alostérica/efeitos dos fármacos , Animais , Benzimidazóis/metabolismo , Benzimidazóis/farmacocinética , Disponibilidade Biológica , Caspases/metabolismo , Proliferação de Células/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Ativação Enzimática/efeitos dos fármacos , Células HEK293 , Proteínas de Choque Térmico HSP70/química , Humanos , Camundongos , Modelos Moleculares , Ácidos Nipecóticos/metabolismo , Ácidos Nipecóticos/farmacocinética , Permeabilidade , Piperidinas/metabolismo , Piperidinas/farmacocinética , Agregados Proteicos/efeitos dos fármacos , Estrutura Terciária de Proteína , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Twenty novel N-diarylalkenyl-piperidinecarboxylic acid derivatives were synthesized and evaluated as gamma-aminobutyric acid uptake inhibitors. The biological assay showed that (R)-1-[4,4-bis(3-phenoxymethyl-2-thienyl)-3-butenyl]-3-piperidinecarboxylic hydrochloride possessed almost as strong GAT1 inhibitory activity as tiagabine. The synthesis and structure-activity relationships are discussed.
Assuntos
Ácidos Carboxílicos/química , Agonistas GABAérgicos/farmacologia , Ácidos Pipecólicos/química , Ácido gama-Aminobutírico/metabolismo , Animais , Transporte Biológico , Ácidos Carboxílicos/síntese química , Química Farmacêutica/métodos , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Agonistas GABAérgicos/química , Humanos , Concentração Inibidora 50 , Modelos Químicos , Neurônios/metabolismo , Ácidos Nipecóticos/química , Ácidos Nipecóticos/farmacologia , Ácidos Pipecólicos/síntese química , Relação Estrutura-Atividade , Tiagabina , Ácido gama-Aminobutírico/farmacocinéticaRESUMO
A series of structurally novel small molecule inhibitors of human alpha-thrombin was prepared to elucidate their structure- activity relationships (SAR), selectivity and activity in vivo. BMS-189090 (5) is identified as a potent, selective, and reversible inhibitor of human alpha-thrombin that is efficacious in vivo in a mice lethality model, and in inhibiting both arterial and venous thrombosis in a rat model.