RESUMO
Development of inhibitor compounds selective against undesirable targets is critical in drug discovery. Selectivity ratios for candidate compounds are evaluated by dividing potencies from two assays assessing the off-target and target. Because all potency measurements have underlying uncertainty, understanding error propagation is essential to interpreting selectivity data. Assay noise introduces ambiguity in the statistical significance of selectivity ratios, particularly at low replicate numbers when compounds are often prioritized for subsequent testing. The ability to differentiate potency results for any pair of compounds in one assay is evaluated using a metric called minimum significant ratio (MSR). Potency results of one compound tested in a pair of assays can be differentiated by the minimum significant selectivity ratio (MSSR). To differentiate selectivity ratios for any pair of compounds, we extend this concept by proposing two new parameters called the minimum significant ratio of selectivity ratios (MSRSR) and confidence in ratio of selectivity ratios (CRSR). Importantly, these tools can be used after a single selectivity measurement. We describe these methods and illustrate their usefulness using structure-activity relationship data from a Janus kinase inhibitor project, in which these tools informed a cogent retesting strategy and enabled rapid and objective decision making.
Assuntos
Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/farmacologia , Janus Quinases/antagonistas & inibidores , Preparações Farmacêuticas/análise , Fenômenos Fisiológicos Celulares , Interpretação Estatística de Dados , Inibidores Enzimáticos/química , Janus Quinases/metabolismo , Relação Estrutura-AtividadeRESUMO
Comprehensive SAR studies were undertaken in the 3,4-diaminocyclobut-3-ene-1,2-dione class of CXCR2/CXCR1 receptor antagonists to explore the role of the heterocycle on chemokine receptor binding affinities, functional activity, as well as oral exposure in rat. The nature of the heterocycle as well as the requisite substitution pattern around the heterocycle was shown to have a dramatic effect on the overall biological profile of this class of compounds. The furyl class, particularly the 4-halo adducts, was found to possess superior binding affinities for both the CXCR2 and CXCR1 receptors, functional activity, as well as oral exposure in rat versus other heterocyclic derivatives.
Assuntos
Ciclobutanos/química , Ciclobutanos/farmacologia , Diaminas/química , Diaminas/farmacologia , Receptores de Interleucina-8A/antagonistas & inibidores , Receptores de Interleucina-8B/antagonistas & inibidores , Animais , Linhagem Celular , Ciclobutanos/síntese química , Diaminas/síntese química , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Camundongos , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
A series of novel and potent 3,4-diamino-2,5-thiadiazole-1-oxides were prepared and found to show excellent binding affinities for CXCR2 and CXCR1 receptors and excellent inhibitory activity of Gro-alpha and IL-8 mediated in vitro hPMN MPO release of CXCR2 and CXCR1 expressing cell lines. On the other hand, a closely related 3,4-diamino-2,5-thiadiazole-dioxide did not show functional activity despite its excellent binding affinities for CXCR2 and CXCR1 in membrane binding assays. A detailed SAR has been discussed in these two closely related structures.
Assuntos
Receptores de Interleucina-8A/antagonistas & inibidores , Receptores de Interleucina-8B/antagonistas & inibidores , Animais , Quimiocina CXCL1/química , Quimiocina CXCL1/farmacologia , Fatores Quimiotáticos/química , Fatores Quimiotáticos/farmacologia , Humanos , Interleucina-8/química , Interleucina-8/farmacologia , Cinética , Neutrófilos/efeitos dos fármacos , Neutrófilos/enzimologia , Óxidos/síntese química , Óxidos/química , Óxidos/farmacocinética , Óxidos/farmacologia , Peroxidase/metabolismo , Ratos , Relação Estrutura-Atividade , Tiadiazóis/síntese química , Tiadiazóis/química , Tiadiazóis/farmacocinética , Tiadiazóis/farmacologiaRESUMO
In neutrophils, growth-related protein-alpha (CXCL1) and interleukin-8 (CXCL8), are potent chemoattractants (Cytokine 14:27-36, 2001; Biochemistry 42:2874-2886, 2003) and can stimulate myeloperoxidase release via activation of the G protein-coupled receptors CXCR1 and CXCR2. The role of CXCR1 and CXCR2 in the pathogenesis of inflammatory responses has encouraged the development of small molecule antagonists for these receptors. The data presented herein describe the pharmacology of 2-hydroxy-N,N-dimethyl-3-{2-[[(R)-1-(5-methyl-furan-2-yl)-propyl]amino]-3,4-dioxo-cyclobut-1-enylamino}-benzamide (Sch527123), a novel antagonist of both CXCR1 and CXCR2. Sch527123 inhibited chemokine binding to (and activation of) these receptors in an insurmountable manner and, as such, is categorized as an allosteric antagonist. Sch527123 inhibited neutrophil chemotaxis and myeloperoxidase release in response to CXCL1 and CXCL8 but had no effect on the response of these cells to C5a or formyl-methionyl-leucyl-phenylalanine. The pharmacological specificity of Sch527123 was confirmed by testing in a diversity profile against a panel of enzymes, channels, and receptors. To measure compound affinity, we characterized [(3)H]Sch527123 in both equilibrium and nonequilibrium binding analyses. Sch527123 binding to CXCR1 and CXCR2 was both saturable and reversible. Although Sch527123 bound to CXCR1 with good affinity (K(d) = 3.9 +/- 0.3 nM), the compound is CXCR2-selective (K(d) = 0.049 +/- 0.004 nM). Taken together, our data show that Sch527123 represents a novel, potent, and specific CXCR2 antagonist with potential therapeutic utility in a variety of inflammatory conditions.
Assuntos
Benzamidas/farmacologia , Ciclobutanos/farmacologia , Receptores de Interleucina-8A/antagonistas & inibidores , Receptores de Interleucina-8B/antagonistas & inibidores , Animais , Benzamidas/química , Ligação Competitiva/efeitos dos fármacos , Sinalização do Cálcio/efeitos dos fármacos , Linhagem Celular , Membrana Celular/metabolismo , Quimiotaxia/efeitos dos fármacos , Complemento C5a/farmacologia , Ciclobutanos/química , Relação Dose-Resposta a Droga , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Humanos , Interleucina-8/metabolismo , Camundongos , Estrutura Molecular , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Ensaio Radioligante , Receptores de Interleucina-8A/genética , Receptores de Interleucina-8A/metabolismo , Receptores de Interleucina-8B/genética , Receptores de Interleucina-8B/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
A novel series of cyclobutenedione centered C(4)-alkyl substituted furanyl analogs was developed as potent CXCR2 and CXCR1 antagonists. Compound 16 exhibits potent inhibitory activities against IL-8 binding to the receptors (CXCR2 Ki=1 nM, IC(50)=1.3 nM; CXCR1 Ki=3 nM, IC(50)=7.3 nM), and demonstrates potent inhibition against both Gro-alpha and IL-8 induced hPMN migration (chemotaxis: CXCR2 IC(50)=0.5 nM, CXCR1 IC(50)=37 nM). In addition, 16 has shown good oral pharmacokinetic profiles in rat, mouse, monkey, and dog.
Assuntos
Química Farmacêutica/métodos , Furanos/química , Furanos/farmacocinética , Receptores de Interleucina-8A/antagonistas & inibidores , Receptores de Interleucina-8B/antagonistas & inibidores , Administração Oral , Animais , Área Sob a Curva , Cães , Desenho de Fármacos , Furanos/síntese química , Humanos , Concentração Inibidora 50 , Interleucina-8/química , Cinética , Camundongos , RatosRESUMO
Structure-activity studies on lead cyclobutenedione 3 led to the discovery of 4 (SCH 527123), a potent, orally bioavailable CXCR2/CXCR1 receptor antagonist with excellent cell-based activity. Compound 4 displayed good oral bioavailability in rat and may be a potential therapeutic agent for the treatment of various inflammatory diseases.
Assuntos
Benzamidas/farmacologia , Ciclobutanos/farmacologia , Receptores de Interleucina-8A/antagonistas & inibidores , Receptores de Interleucina-8B/antagonistas & inibidores , Administração Oral , Animais , Benzamidas/administração & dosagem , Benzamidas/síntese química , Disponibilidade Biológica , Ciclobutanos/administração & dosagem , Ciclobutanos/síntese química , Estrutura Molecular , Ratos , Receptores de Interleucina-8A/metabolismo , Receptores de Interleucina-8B/metabolismo , Relação Estrutura-AtividadeRESUMO
Structure-activity relationship study of bipiperidine amide 1 has identified the reverse bipiperidine amide 4a as a CC chemokine-3 (CCR3) receptor antagonist. Optimization of the structure-activity relationship of compound 4a has resulted in the identification of a CCR3 antagonist 4i as well as a CCR3 agonist 13.
Assuntos
Amidas/síntese química , Amidas/farmacologia , Piperidinas/síntese química , Piperidinas/farmacologia , Receptores de Quimiocinas/agonistas , Receptores de Quimiocinas/antagonistas & inibidores , Quimiocina CCL11 , Quimiocinas CC/metabolismo , Fatores Quimiotáticos de Eosinófilos/metabolismo , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Humanos , Ligação Proteica , Receptores CCR3 , Receptores de HIV/agonistas , Receptores de HIV/antagonistas & inibidores , Relação Estrutura-AtividadeRESUMO
Bipiperidine amide 1 has been identified as a CC chemokine receptor 3 (CCR3) antagonist. Optimization of its structure-activity relationship has resulted in the identification of cis (R,R)-4-[(3,4-dichlorophenyl)methyl]-3-hydroxymethyl-1'(6-quinolinylcarbonyl)-1,4'-bipiperidine 14n, which exhibits potent receptor affinity and inhibition of both calcium flux and eosinophil chemotaxis.
Assuntos
Amidas/síntese química , Amidas/farmacologia , Piperidinas/síntese química , Piperidinas/farmacologia , Receptores de Quimiocinas/antagonistas & inibidores , Animais , Humanos , Estrutura Molecular , Receptores CCR3 , Relação Estrutura-AtividadeRESUMO
Study of the CC chemokine receptor 3 (CCR3) has been limited to using radiolabeled agonist chemokines. A small molecule CCR3 antagonist, 2-[(6-amino-2-benzothiazolyl)thio]-N-[1-[(3,4-dichlorylphenyl)methyl]-4-piperidinyl]acetamide, Banyu (I), was tritiated and used for pharmacological studies. Banyu (I) has a K(d) of 5.0+/-0.4 and 4.3+/-1.8 nM on human CCR3 transfectants and eosinophils, and noncompetitively inhibits [125I]eotaxin binding and eotaxin-induced [35S]guanosine-5'-O-(3-thiotriphosphate) ([35S]GTPgammaS) binding. The proportion of [125I]eotaxin: [3H]Banyu (I) binding sites in eosinophils or transfectants was 35% or 13%, although both binding sites were overexpressed in transfectants. CCR3 spontaneously couples to G-proteins in CCR3 transfectants, demonstrated by changes in basal and eotaxin-induced [35S]GTPgammaS binding under reduced NaCl and GDP concentrations. Consequently, Banyu (I) was identified as an inverse agonist. In contrast, CCL18 and I-TAC (interferon-inducible T cell alpha-chemoattractant) were neutral antagonists, inhibiting eotaxin-induced [35S]GTPgammaS binding, with minimal effect on basal coupling of CCR3 to G proteins. Eotaxin, eotaxin-2 and monocyte chemoattractant protein (MCP)-4 are full agonists inducing [35S]GTPgammaS binding; eotaxin-3, MCP-3, RANTES (regulated on activation normal T cell expressed and secreted), vMIP-I (Kaposi's sarcoma-associated herpesvirus macrophage inflammatory protein-) and vMIP-II are partial agonists, indicating that this is a sensitive method to quantitate agonist efficacy.