RESUMO
A hit to lead process to identify reversible, orally available ADP receptor (P2Y12) antagonists lead compounds is described. High throughput screening afforded 1. Optimization of 1, using parallel synthesis methods, a methyl scan to identify promising regions for optimization, and exploratory SAR on these regions, provided 22 and 23. Compound 23 is an orally available, competitive reversible antagonist (KBâ¯=â¯94â¯nM for inhibition of ADP-induced platelet aggregation). It exhibits high metabolic stability in human, rat and dog liver microsomes and is orally absorbed. Although plasma level after oral dosing of 22 and 23 to rats is low, reasonable levels were achieved to merit extensive lead optimization of this structural class.
Assuntos
Fluorenos/farmacologia , Receptores Purinérgicos P2Y12/metabolismo , Administração Oral , Animais , Cães , Relação Dose-Resposta a Droga , Fluorenos/administração & dosagem , Fluorenos/química , Ensaios de Triagem em Larga Escala , Humanos , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Agregação Plaquetária/efeitos dos fármacos , Ratos , Relação Estrutura-AtividadeRESUMO
We report here the design and synthesis of a novel series of benzylamines that are potent and selective inhibitors of uPA with promising oral availability in rat. Further evaluation of one representative (ZK824859) of the new structural class showed that this compound lowered clinical scores when dosed in either acute or chronic mouse EAE models, suggesting that uPA inhibitors of this type could be useful for the treatment of multiple sclerosis.
Assuntos
Benzilaminas/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Inibidores de Serina Proteinase/uso terapêutico , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Animais , Benzilaminas/síntese química , Benzilaminas/química , Benzilaminas/farmacocinética , Sítios de Ligação , Feminino , Humanos , Camundongos , Modelos Moleculares , Estrutura Molecular , Ratos , Inibidores de Serina Proteinase/síntese química , Inibidores de Serina Proteinase/química , Inibidores de Serina Proteinase/farmacocinética , Relação Estrutura-Atividade , Ativador de Plasminogênio Tipo Uroquinase/químicaRESUMO
Utilizing a structure based design approach, combined with extensive medicinal chemistry execution, highly selective, potent and novel BACE1 inhibitor 8 (BACE1 Alpha assay IC50=8nM) was made from a weak µM potency hit in an extremely efficient way. The detailed SAR and general design approaches will be discussed.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Desenho de Fármacos , Isoquinolinas/farmacologia , Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacologia , Tiofenos/farmacologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Relação Dose-Resposta a Droga , Humanos , Isoquinolinas/química , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteases/química , Relação Estrutura-Atividade , Tiofenos/químicaRESUMO
The structure-activity relationship of a series of dihydroisoquinoline BACE-1 inhibitors is described. Application of structure-based design to screening hit 1 yielded sub-micromolar inhibitors. Replacement of the carboxylic acid of 1 was guided by X-ray crystallography, which allowed the replacement of a key water-mediated hydrogen bond. This work culminated in compounds such as 31, which possess good BACE-1 potency, excellent permeability and a low P-gp efflux ratio.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico/química , Desenho de Fármacos , Isoquinolinas/farmacologia , Inibidores de Proteases/farmacologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Catálise , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Humanos , Isoquinolinas/síntese química , Isoquinolinas/química , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , Relação Estrutura-AtividadeRESUMO
Structure-activity relationship (SAR) of a novel, potent and metabolically stable series of benzo [3.2.1] bicyclic sulfonamide-pyrazoles as γ-secretase inhibitors are described. Compounds that are efficacious in reducing the cortical Aßx-40 levels in FVB mice via oral dose, as well as those with high selectivity over Notch, are highlighted.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Pirazóis/farmacologia , Sulfonamidas/farmacologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Camundongos , Pirazóis/química , Relação Estrutura-Atividade , Sulfonamidas/químicaRESUMO
In this Letter we report the synthesis and evaluation of a series of non-amidine inhibitors of Urokinase Plasminogen Activator (uPA). Starting from compound 1, a significant change provided compounds in which the amidine, binding in the S1 pocket, was replaced with a primary amine. Further modifications led to the identification of potent, selective, and orally bioavailable uPA inhibitors.
Assuntos
Benzilaminas/química , Inibidores de Serina Proteinase/química , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Administração Oral , Amidinas/química , Animais , Sítios de Ligação , Cristalografia por Raios X , Humanos , Ratos , Inibidores de Serina Proteinase/administração & dosagem , Inibidores de Serina Proteinase/síntese química , Relação Estrutura-Atividade , Ativador de Plasminogênio Tipo Uroquinase/metabolismoRESUMO
A total synthesis of N-desmethyl thalassospiramide C, a unique strained macrocyclic proteobacterial depsipeptide, enabled a detailed crystallographic study of its covalent complex with cathepsin K, a member of a medicinally important family of cysteine proteases. The study provides support for the mechanism of action, and the insight gained can be used for structure-based drug design targeting these calpain proteases.
Assuntos
Catepsina K/química , Inibidores de Cisteína Proteinase/síntese química , Cisteína/química , Serina Endopeptidases/química , Inibidores de Cisteína Proteinase/química , Estrutura MolecularRESUMO
ADP plays a key role in platelet aggregation which has led to the development of antiplatelet drugs that target the P2Y12 receptor. The aim of this study was to characterize the effects of two novel P2Y12 receptor antagonists, BX 667 and its active metabolite BX 048, on platelets. BX 667 and BX 048 block the binding of 2MeSADP to platelets and antagonize ADP-induced platelet aggregation in human, dog and rat washed platelets. Both compounds were shown to be reversible inhibitors of platelet aggregation. BX 048 prevents the decrease in cAMP induced by treatment of platelets with ADP. The specificity of BX 667 and BX 048 was demonstrated against cell lines expressing P2Y1 and P2Y6 as well as against a panel of receptors and enzymes. Taken all together these data show that both BX 048 and BX 667 are potent P2Y12 antagonists with high specificity which, in the accompanying paper are demonstrated to behave predictably in vivo.
Assuntos
Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Cetoácidos/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Antagonistas do Receptor Purinérgico P2 , Quinolinas/farmacologia , Receptores Purinérgicos P2/metabolismo , Difosfato de Adenosina/química , Animais , Cálcio/metabolismo , Cães , Avaliação Pré-Clínica de Medicamentos , Humanos , Técnicas In Vitro , Ligantes , Modelos Biológicos , Agregação Plaquetária/efeitos dos fármacos , Ligação Proteica , Ratos , Receptores Purinérgicos P2Y12 , Especificidade da EspécieRESUMO
We have discovered a novel small-molecule (3-phosphinoylpropionic acid) inhibitor of activated thrombin activatable fibrinolysis inhibitor (TAFIa), BX 528, which had an IC (50) of 2 nM in an enzymatic assay and 50 nM in an in-vitro clot lysis assay, with 3,500- to 35,000-fold selectivity against other carboxypeptidases, such as CPN, CPZ and CPD, and 5- and 12-fold selectivity against CPE (CPH) and CPB, respectively. At 10 micro M, BX 528 had no significant activity (<50% inhibition or antagonism) in a panel of 137 enzymes and receptors. It had no effects on blood coagulation and platelet aggregation up to 300 and 10 micro M, respectively. The plasma half-life following intravenous administration was 0.85 hours in rats and 4.5 hours in dogs. No significant metabolism was detected in human, dog or rabbit hepatic microsomes, and no significant inhibition of cytochrome P450 3A4 and 2D6 up to 30 micro M. No cytotoxic or cell proliferative effects were found in three hepatic and renal cell lines up to 300 micro M and no mutagenic activity was seen in the Ames II screen. There were no significant hemodynamic effects in rats and dogs up to 100 and 30 mg/kg with peak plasma drug concentrations of approximately 1,000 and 300 micro M, respectively. In an in-vivo complement activation model in guinea pigs, BX 528 showed minimal inhibition of plasma CPN activity up to 60 mg/kg with peak plasma concentrations up to 250 micro M. Thus, these data demonstrate that BX 528 is a novel, potent, selective and safe TAFIa inhibitor.
Assuntos
Carboxipeptidase B2/antagonistas & inibidores , Inibidores Enzimáticos/farmacocinética , Animais , Coagulação Sanguínea/efeitos dos fármacos , Carboxipeptidases/antagonistas & inibidores , Proliferação de Células/efeitos dos fármacos , Cães , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Cobaias , Meia-Vida , Humanos , Concentração Inibidora 50 , Microssomos Hepáticos/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Propionatos/farmacocinética , Propionatos/farmacologia , Coelhos , Ratos , Especificidade por SubstratoRESUMO
We have discovered a novel small-molecule TAFIa inhibitor, BX 528, which is potent, highly selective against other carboxypeptidases and safe. The present study was to determine if BX 528 can enhance exogenous and endogenous thrombolysis in four different animal models. In the first three models, a thrombus was induced by FeCl (2) (dogs) or laser (rats) injury of the femoral artery, or formed ex vivo and implanted in the jugular vein in rabbits. A low dose of exogenous t-PA was given to induce a low-level thrombolysis on an established thrombus. Co-treatment with BX 528 further enhanced the thrombolytic effects induced by the exogenous t-PA and, thus, reduced thrombosis in all three animal models. In a second rat model, fibrin deposition in the lungs was induced by batroxobin, which was spontaneously resolved in 30 minutes due to the activation of endogenous fibrinolysis. Pre-treatment with lipopolysaccharide (LPS) attenuated this spontaneous fibrinolysis. Co-treatment with 10 mg/kg BX 528 prevented the LPS-induced attenuation of endogenous fibrinolysis. Thus, these studies demonstrated that inhibition of TAFIa by BX 528, our newly discovered small-molecule TAFIa inhibitor, enhanced both the exogenous (induced by a low dose of t-PA) and endogenous (LPS-induced resistance) thrombolysis without increasing the bleeding risk in four different animal models of thrombosis in different species (rat, dog and rabbit) employing different thrombogenic stimuli (FeCl (2) , laser, ex vivo and batroxobin) to induce thrombus formation in different tissues (artery, vein and lung microcirculation).
Assuntos
Carboxipeptidase B2/antagonistas & inibidores , Fibrinólise/efeitos dos fármacos , Fibrinolíticos/farmacologia , Trombose/tratamento farmacológico , Animais , Modelos Animais de Doenças , Cães , Sinergismo Farmacológico , Inibidores Enzimáticos/farmacologia , Lipopolissacarídeos/farmacologia , Propionatos/farmacologia , Coelhos , Ratos , Ativador de Plasminogênio Tecidual/farmacologiaRESUMO
Irreversible platelet inhibitors, such as aspirin and clopidogrel, have limited anti-thrombotic efficacy in the clinic due to their bleeding risk. We have developed an orally active reversible P2Y(12) receptor antagonist, BX 667. The aim of this study was to determine if the reversible antagonist BX 667 had a greater therapeutic index than the irreversible P2Y(12) receptor antagonist clopidogrel. Since BX 667 is rapidly converted to its active metabolite BX 048 in rats, we first injected BX 048 intravenously (iv) in a rat arterial venous (A-V) shunt model of thrombosis. BX 048 dose- and concentration-dependently attenuated thrombosis. When administered orally, BX 667 and clopidogrel had similar efficacy, but BX 667 caused less bleeding than clopidogrel. In a rat model of a platelet-rich thrombus induced by vessel injury with FeCl(2), both BX 667 and clopidogrel exhibited higher levels of thrombus inhibition after oral administration compared to their potency in the A-V shunt model. Again, BX 667 caused less bleeding than clopidogrel. In a dog cyclic flow model, iv injection of either BX 667 or clopidogrel dose-dependently reduced thrombus formation with lower bleeding for BX 667 than clopidogrel. Inhibition of thrombosis was highly correlated with inhibition of ADP-induced platelet aggregation in these animal models. In dogs pre-treated with aspirin, BX 667 maintained its wider therapeutic index, measured by inhibition of platelet aggregation over bleeding, compared to the aspirin-clopidogrel combination. These data demonstrate that the reversible P2Y(12) receptor antagonist, BX 667, has a wider therapeutic index than clopidogrel in experimental models of thrombosis.
Assuntos
Proteínas de Membrana/antagonistas & inibidores , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Antagonistas do Receptor Purinérgico P2 , Trombose/prevenção & controle , Animais , Derivação Arteriovenosa Cirúrgica , Lesões das Artérias Carótidas/tratamento farmacológico , Clopidogrel , Modelos Animais de Doenças , Cães , Técnicas In Vitro , Masculino , Estrutura Molecular , Inibidores da Agregação Plaquetária/sangue , Inibidores da Agregação Plaquetária/química , Ratos , Ratos Sprague-Dawley , Receptores Purinérgicos P2 , Receptores Purinérgicos P2Y12 , Ticlopidina/análogos & derivados , Ticlopidina/farmacologiaRESUMO
A novel class of preorganized U-shape calix[4]arene clefts, dicationic salts 3a,c,e.2Cl, 3b.2PF(6)(), and 3f.2Br, consisting of one cone calix[4]arene and two bipyridine residues being linked by an aliphatic chain, have been designed and synthesized as precursors for self-assembly of calix[4]arene [2]catenanes by utilizing pi-stacking interactions between the hydroquinone and bipyridinium units. Conformationally flexible 6.2PF(6)() and cone 10.2Cl, whose conformation is fixed by two propyloxy groups on the lower rim, were also prepared in order to explore the effects of conformation and hydrogen bonding of the calix[4]arene moiety on self-assembly. For all reactions, bis-p-phenylene-34-crown ether-10 (11) was employed as the donor component. Alternate cone [2]catenane 13.4Cl is obtained in 8% yield from reaction of ethylene-incorporating 3a.2Cl and 1,4-bis(bromomethyl)benzene (12a). Three cone and one conformationally flexible [2]catenanes were obtained in moderate to good yields from reactions of propylene-incorporating 3b.PF(6)() and 3c.2Cl with 12a, 1,3-bis(bromomethyl)benzene (12b) or 4,4'-(bromomethyl)biphenyl (12c). Both cone and partial cone [2]catenanes were generated in moderate yields from butylene-incorporating 3c.2Cl with four tert-butyl groups on the calix[4]arene moiety and with 12a. In contrast, only cone [2]catenane was obtained from similar tert-butyl-free cleft 3d.2Cl. Cone and conformationally flexible [2]catenanes were obtained in moderate yields, respectively, from the reactions of 3d.2Cl and 3e.2Cl with 12c. No catenanes were isolated from reaction of phenylene-incorporating 3f.2Br or 6.2Cl, whereas reaction of 10.2Cl afforded cone [2]catenane in low yield. It was demonstrated that hydrogen bonding, which may be destroyed after catenation, within the calix[4]arene moiety is crucial for efficient self-assembly of the [2]catenanes. The dynamic (1)H NMR and absorption spectra and luminescent properties of the [2]catenanes were investigated, which reveal that incorporation of calix[4]arene into the tetracationic cyclophane reduces pi-stacking interactions between the donor and acceptor units and catenation has substantial influence on conformational distributions of the calix[4]arene moiety. The results demonstrate the versatility of calix[4]arene derivatives as building blocks in the construction of supramolecular structures.
RESUMO
Alzheimer's disease (AD) is a devastating neurodegenerative disease affecting millions of people. ß-secretase-1 (BACE1), an enzyme involved in the processing of the amyloid precursor protein (APP) to form Aß is a validated target for AD. Herein, the authors develop and validate a novel binding assay for BACE1 using the AlphaScreen platform that is amenable for high-throughput screening (HTS). Small-molecule BACE1 inhibitors of the hydroxyethylamine, hydantoin, and sulfamide classes were functionalized by biotin PEG linkers of varying lengths forming probes that were bound to streptavidin donor beads. BACE1 was coupled to nickel-chelate acceptor beads. Upon mixing, probes designed from all three classes registered high signal-to-background values in the AlphaScreen binding assay, where the interaction between probe and BACE1 was completely blocked by free parent compound. A probe from the hydantoin class was chosen for further optimization, where the final assay conditions of 50 nM BACE and 250 nM probe were used and Z(') values >0.75 were commonly observed. IC50 values determined by the AlphaScreen assay format exhibited ~10-fold greater sensitivity when compared with a fluorescence polarization-based activity assay. The assay was miniaturized to a 1536-well format for HTS, in which 525 000 compounds were screened.
Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Bibliotecas de Moléculas Pequenas/farmacologia , Doença de Alzheimer/enzimologia , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Humanos , Hidantoínas , Concentração Inibidora 50 , Sensibilidade e EspecificidadeRESUMO
Heat-shock protein-90 is an attractive target for anticancer drugs, as heat-shock protein-90 blockers such as the ansamycin 17-(allylamino)-17-demethoxygeldanamycin greatly reduce the expression of many signaling molecules that are disregulated in cancer cells and are key drivers of tumor growth and metastasis. While 17-(allylamino)-17-demethoxygeldanamycin has shown promise in clinical trials, this compound class has significant template-related drawbacks. In this paper, we describe a new, potent non-ansamycin small-molecule inhibitor of heat-shock protein-90, BX-2819, containing resorcinol and triazolothione rings. Structural studies demonstrate binding of BX-2819 to the ADP/ATP-binding pocket of heat-shock protein-90. The compound blocked expression of heat-shock protein-90 client proteins in cancer cell lines and inhibited cell growth with a potency similar to 17-(allylamino)-17-demethoxygeldanamycin. In a panel of four cancer cell lines, BX-2819 blocked growth with an average IC(50) value of 32 nM (range of 7-72 nM). Efficacy studies demonstrated that treatment with BX-2819 significantly inhibited the growth of NCI-N87 and HT-29 tumors in nude mice, consistent with pharmacodynamic studies showing inhibition of heat-shock protein-90 client protein expression in tumors for greater than 16 h after dosing. These data support further studies to assess the potential of BX-2819 and related analogs for the treatment of cancer.
Assuntos
Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Triazóis/farmacologia , Animais , Benzoquinonas/química , Benzoquinonas/farmacologia , Linhagem Celular Tumoral , Simulação por Computador , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Proteínas de Choque Térmico HSP90/metabolismo , Células HT29 , Humanos , Lactamas Macrocíclicas/química , Lactamas Macrocíclicas/farmacologia , Camundongos , Camundongos Nus , Transplante Heterólogo , Triazóis/química , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
This article reports the crystal structures of inhibitors of the functional form of thrombin-activatable fibrinolysis inhibitor (TAFIa). In vivo experiments indicate that selective inhibitors of TAFIa would be useful in the treatment of heart attacks. Since TAFIa rapidly degrades in solution, the homologous protein porcine pancreatic carboxypeptidase B (pp-CpB) was used in these crystallography studies. Both TAFIa and pp-CpB are zinc-based exopeptidases that are specific for basic residues. The final development candidate, BX 528, is a potent inhibitor of TAFIa (2 nM) and has almost no measurable effect on the major selectivity target, carboxypeptidase N. BX 528 was designed to mimic the tripeptide Phe-Val-Lys. A sulfonamide replaces the Phe-Val amide bond and a phosphinate connects the Val and Lys groups. The phosphinate also chelates the active-site zinc. The electrostatic interactions with the protein mimic those of the natural substrate. The primary amine in BX 528 forms a salt bridge to Asp255 at the base of the S1' pocket. The carboxylic acid interacts with Arg145 and the sulfonamide is hydrogen bonded to Arg71. Isopropyl and phenyl groups replace the side chains of Val and Phe, respectively. A series of structures are presented here that illustrate the evolution of BX 528 from thiol-based inhibitors that mimic a free C-terminal arginine. The first step in development was the replacement of the thiol with a phosphinate. This caused a precipitous drop in binding affinity. Potency was reclaimed by extending the inhibitors into the downstream binding sites for the natural substrate.
Assuntos
Carboxipeptidase B/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Sítios de Ligação , Carboxipeptidase B/química , Carboxipeptidase B2/química , Cristalografia por Raios X/métodos , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Estrutura MolecularRESUMO
A series of compounds was rationally designed as inhibitors of dimer formation of the inducible isoform of nitric oxide synthase, and subsequent nitric oxide production. The conformation of two fragments obtained from a crystal structure was utilized to design a tether connecting those same two fragments. The resulting compounds were potent dimerization inhibitors that bound to the enzyme in a similar conformation as the fragments.
Assuntos
Inibidores Enzimáticos/síntese química , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Sítios de Ligação , Linhagem Celular Tumoral , Química Farmacêutica/métodos , Cristalização , Cristalografia por Raios X , Dimerização , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Humanos , Modelos Químicos , Conformação MolecularRESUMO
A novel series of cyclic potent, selective, small molecule, thiol-based inhibitors of activated thrombin activatable fibrinolysis inhibitor (TAFIa) and the crystal structures of TAFIa inhibitors bound to porcine pancreatic carboxypeptidase B are described. Three series of cyclic arginine and lysine mimetic inhibitors vary significantly in their selectivity against other human basic carboxypeptidases, carboxypeptidase N and carboxypeptidase B. (-)2a displays TAFIa IC50 = 3 nM and 600-fold selectivity against CPN. Inhibition of TAFIa with (rac)2a resulted in dose dependent acceleration of human plasma clot lysis in vitro and was efficacious as an adjunct to tPA in an in vivo rabbit jugular vein thrombolysis model.
Assuntos
Ácido 3-Mercaptopropiônico/farmacologia , Carboxipeptidase B2/antagonistas & inibidores , Fibrinolíticos/síntese química , Animais , Arginina , Carboxipeptidase B/antagonistas & inibidores , Cristalografia por Raios X , Fibrinolíticos/farmacocinética , Fibrinolíticos/farmacologia , Humanos , Lisina , Lisina Carboxipeptidase/antagonistas & inibidores , Mimetismo Molecular , Peptídeos Cíclicos , Coelhos , Relação Estrutura-Atividade , Especificidade por Substrato , SuínosRESUMO
A new series of 1-(1,3-benzodioxol-5-ylmethyl)-3-[4-(1H-Imidazol-1-yl)phenoxy]-piperidine analogs were designed and identified as potent and selective inhibitors of NO formation based both on the crystal structure of a murine iNOS Delta114 monomer domain/ inhibitor complex and inhibition of the NO formation in human A172 cell assays. Compound 12S showed high potency and high iNOS selectivity versus nNOS and eNOS.
Assuntos
Química Farmacêutica/métodos , Imidazóis/síntese química , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico/antagonistas & inibidores , Piperidinas/química , Animais , Linhagem Celular Tumoral , Dimerização , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Imidazóis/farmacologia , Concentração Inibidora 50 , Camundongos , Modelos Químicos , Conformação Molecular , Óxido Nítrico Sintase Tipo I/antagonistas & inibidores , Óxido Nítrico Sintase Tipo III/antagonistas & inibidores , Piperidinas/síntese química , Piperidinas/farmacologiaRESUMO
Based on the lead compound BX-517, a series of C-4' substituted indolinones have been synthesized and evaluated for PDK1 inhibition. Modification at C-4' of the pyrrole afforded potent compounds (7b and 7d) with improved solubility and ADME properties. In this letter, we describe the synthesis, selectivity profile, and pharmacokinetic data of selected compounds.
Assuntos
Indóis/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Ureia/análogos & derivados , Proteínas Quinases Dependentes de 3-Fosfoinositídeo , Linhagem Celular Tumoral , Humanos , Indóis/farmacologia , Inibidores de Proteínas Quinases/química , Ureia/química , Ureia/farmacologiaRESUMO
This paper presents the crystal structure of porcine pancreatic carboxypeptidase B (pp-CpB) in complex with a variety of thiol-based inhibitors that were developed as antagonists of activated thrombin-activatable fibrinolysis inhibitor (TAFIa). Recent studies have indicated that a selective inhibitor of TAFIa could enhance the efficacy of existing thrombolytic agents for the treatment of acute myocardial infarction, one of the most prevalent forms of heart attacks. Unfortunately, activated TAFIa rapidly degrades in solution and cannot be used for crystallographic studies. In contrast, porcine pancreatic CpB is stable at room temperature and is available from commercial sources. Both pancreatic CpB and TAFIa are zinc-based exopeptidases, and the proteins share a 47% sequence identity. The homology improves considerably in the active site where nearly all of the residues are conserved. The inhibitors used in this study were designed to mimic a C-terminal arginine residue, one of the natural substrates of TAFIa. The X-ray structures show that the thiol group chelates the active site zinc, the carboxylic acid forms a salt bridge to Arg145, and the guanidine group forms two hydrogen bonds to Asp255. A meta-substituted phenyl was introduced into our inhibitors to reduce conformational freedom. This modification vastly improved the selectivity of compounds against other exopeptidases that cleave basic residues. Comparisons between structures indicate that selectivity derives from the interaction between the guanidine group in the inhibitors and an acidic active site residue. The location of this acidic residue is not conserved in the various carboxypeptidases.