RESUMO
The list of ADCs in the clinic continues to grow, bolstered by the success of first two marketed ADCs: ADCETRIS® and Kadcyla®. Currently, there are 40 ADCs in various phases of clinical development. However, only 34 of these have published their structures. Of the 34 disclosed structures, 24 of them use a linkage to the thiol of cysteines on the monoclonal antibody. The remaining 10 candidates utilize chemistry to surface lysines of the antibody. Due to the inherent heterogeneity of conjugation to the multiple lysines or cysteines found in mAbs, significant research efforts are now being directed toward the production of discrete, homogeneous ADC products, via site-specific conjugation. These site-specific conjugations may involve genetic engineering of the mAb to introduce discrete, available cysteines or non-natural amino acids with an orthogonally-reactive functional group handle such as an aldehyde, ketone, azido, or alkynyl tag. These site-specific approaches not only increase the homogeneity of ADCs but also enable novel bio-orthogonal chemistries that utilize reactive moieties other than thiol or amine. This broadens the diversity of linkers that can be utilized which will lead to better linker design in future generations of ADCs.
Assuntos
Anticorpos Monoclonais/química , Imunoconjugados/química , Preparações Farmacêuticas/química , Engenharia de Proteínas/métodos , Cisteína/química , Lisina/químicaRESUMO
Structure-activity relationship (SAR) studies on a highly potent series of arylamide FMS inhibitors were carried out with the aim of improving FMS kinase selectivity, particularly over KIT. Potent compound 17r (FMS IC50 0.7 nM, FMS cell IC50 6.1 nM) was discovered that had good PK properties and a greater than fivefold improvement in selectivity for FMS over KIT kinase in a cellular assay relative to the previously reported clinical candidate 4. This improved selectivity was manifested in vivo by no observed decrease in circulating reticulocytes, a measure of bone safety, at the highest studied dose. Compound 17r was highly active in a mouse pharmacodynamic model and demonstrated disease-modifying effects in a dose-dependent manner in a strep cell wall-induced arthritis model of rheumatoid arthritis in rats.
Assuntos
Amidas/farmacologia , Compostos Heterocíclicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Amidas/síntese química , Amidas/química , Animais , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Masculino , Camundongos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Ratos , Ratos Sprague-Dawley , Receptor de Fator Estimulador de Colônias de Macrófagos/metabolismo , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Complement C1s protease inhibitors have potential utility in the treatment of diseases associated with activation of the classical complement pathway such as humorally mediated graft rejection, ischemia-reperfusion injury (IRI), vascular leak syndrome, and acute respiratory distress syndrome (ARDS). The utility of biphenylsulfonyl-thiophene-carboxamidine small-molecule C1s inhibitors are limited by their poor in vivo pharmacokinetic properties. Pegylation of a potent analog has provided compounds with good potency and good in vivo pharmacokinetic properties.
Assuntos
Amidas/química , Complemento C1s/antagonistas & inibidores , Desenho de Fármacos , Polietilenoglicóis/química , Inibidores de Proteases/síntese química , Tiofenos/química , Animais , Complemento C1s/metabolismo , Meia-Vida , Inibidores de Proteases/química , Inibidores de Proteases/farmacocinética , RatosRESUMO
Macrophages, upon phagocytosing endospores of Bacillus anthracis, up-regulate the expression of the immunological isoform of nitric oxide synthase, NOS 2, concomitant with production of nitric oxide (NOâ¢) from metabolism of L -arginine. We have previously demonstrated that macrophages that secrete NO⢠kill the bacilli of B. anthracis. To circumvent this microbicidal activity of NOâ¢, B. anthracis has evolved pathways that include the enzyme arginase, which metabolizes L: -arginine to ornithine and urea. Compounds that inhibit arginase might, therefore, offer a therapeutic approach to controlling B. anthracis infection. 2(S)-Amino-6-boronohexanoic acid (ABH) has been reported to be an inhibitor of mammalian arginase. In this study, we explore the inhibitory effect of ABH against B. anthracis arginase and its potential for future development, as an effective therapeutic agent against microbial infection. We found that ABH is an inhibitor of bacterial arginase in several different endospore strains of B. anthracis. Further, ABH inhibits neither the phagocytosis of these endospores nor the up-regulation of NOS 2 concomitant with secretion of NOâ¢. These findings set the stage to determine how efficacious ABH will be in promoting NOâ¢-mediating killing of B. anthracis.
Assuntos
Aminocaproatos/metabolismo , Arginase/antagonistas & inibidores , Bacillus anthracis/enzimologia , Compostos de Boro/metabolismo , Inibidores Enzimáticos/metabolismo , Animais , Proteínas de Bactérias/antagonistas & inibidores , Linhagem Celular , Macrófagos/efeitos dos fármacos , Macrófagos/microbiologia , CamundongosRESUMO
A class of potent inhibitors of colony-stimulating factor-1 receptor (CSF-1R or FMS), as exemplified by 8 and 21, was optimized to improve pharmacokinetic and pharmacodynamic properties and potential toxicological liabilities. Early stage absorption, distribution, metabolism, and excretion assays were employed to ensure the incorporation of druglike properties resulting in the selection of several compounds with good activity in a pharmacodynamic screening assay in mice. Further investigation, utilizing the type II collagen-induced arthritis model in mice, culminated in the selection of anti-inflammatory development candidate JNJ-28312141 (23, FMS IC(50) = 0.69 nM, cell assay IC(50) = 2.6 nM). Compound 23 also demonstrated efficacy in rat adjuvant and streptococcal cell wall-induced models of arthritis and has entered phase I clinical trials.
Assuntos
Anti-Inflamatórios não Esteroides/síntese química , Imidazóis/síntese química , Piperidinas/síntese química , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Artrite Experimental/tratamento farmacológico , Artrite Experimental/etiologia , Artrite Experimental/patologia , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Feminino , Humanos , Imidazóis/farmacocinética , Imidazóis/farmacologia , Técnicas In Vitro , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Piperidinas/farmacocinética , Piperidinas/farmacologia , Conformação Proteica , Ratos , Ratos Endogâmicos Lew , Receptor de Fator Estimulador de Colônias de Macrófagos/química , Solubilidade , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
During efforts to improve the bioavailability of FMS kinase inhibitors 1 and 2, a series of saturated and aromatic 4-heterocycles of reduced basicity were prepared and evaluated in an attempt to also improve the cardiovascular safety profile over lead arylamide 1, which possessed ion channel activity. The resultant compounds retained excellent potency and exhibited diminished ion channel activity.
Assuntos
Amidas/farmacologia , Compostos Heterocíclicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Amidas/síntese química , Amidas/química , Relação Dose-Resposta a Droga , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Modelos Moleculares , Estrutura Molecular , Oxirredução , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
We have identified RWJ-671818 (8) as a novel, low molecular weight, orally active inhibitor of human alpha-thrombin (K(i) = 1.3 nM) that is potentially useful for the acute and chronic treatment of venous and arterial thrombosis. In a rat deep venous thrombosis model used to assess antithrombotic efficacy, oral administration of 8 at 30 and 50 mg/kg reduced thrombus weight by 87 and 94%, respectively. In an anesthetized rat antithrombotic model, where electrical stimulation of the carotid artery created a thrombus, 8 prolonged occlusion time 2- and 3-fold at 0.1 and 1.0 mg/kg, i.v., respectively, and more than doubled activated clotting time and activated partial thromboplastin time at the higher dose. This compound had excellent oral bioavailability of 100% in dogs with an estimated half-life of approximately 3 h. On the basis of its noteworthy preclinical data, 8 was advanced into human clinical trials and successfully progressed through phase 1 studies.
Assuntos
Anticoagulantes/síntese química , Fibrinolíticos/síntese química , Guanidinas/síntese química , Pirazinas/síntese química , Trombina/antagonistas & inibidores , Motivos de Aminoácidos , Animais , Anticoagulantes/farmacocinética , Anticoagulantes/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Células CACO-2 , Cristalografia por Raios X , Citocromo P-450 CYP3A , Inibidores do Citocromo P-450 CYP3A , Cães , Método Duplo-Cego , Eletrocardiografia , Feminino , Fibrinolíticos/farmacocinética , Fibrinolíticos/farmacologia , Guanidinas/farmacocinética , Guanidinas/farmacologia , Cobaias , Frequência Cardíaca/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Humanos , Técnicas In Vitro , Masculino , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Pirazinas/farmacocinética , Pirazinas/farmacologia , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/antagonistas & inibidores , Relação Estrutura-Atividade , Trombina/química , Trombose Venosa/sangue , Trombose Venosa/tratamento farmacológicoRESUMO
There is increasing evidence that tumor-associated macrophages promote the malignancy of some cancers. Colony-stimulating factor-1 (CSF-1) is expressed by many tumors and is a growth factor for macrophages and mediates osteoclast differentiation. Herein, we report the efficacy of a novel orally active CSF-1 receptor (CSF-1R) kinase inhibitor, JNJ-28312141, in proof of concept studies of solid tumor growth and tumor-induced bone erosion. H460 lung adenocarcinoma cells did not express CSF-1R and were not growth inhibited by JNJ-28312141 in vitro. Nevertheless, daily p.o. administration of JNJ-28312141 caused dose-dependent suppression of H460 tumor growth in nude mice that correlated with marked reductions in F4/80(+) tumor-associated macrophages and with increased plasma CSF-1, a possible biomarker of CSF-1R inhibition. Furthermore, the tumor microvasculature was reduced in JNJ-28312141-treated mice, consistent with a role for macrophages in tumor angiogenesis. In separate studies, JNJ-28312141 was compared with zoledronate in a model in which MRMT-1 mammary carcinoma cells inoculated into the tibias of rats led to severe cortical and trabecular bone lesions. Both agents reduced tumor growth and preserved bone. However, JNJ-28312141 reduced the number of tumor-associated osteoclasts superior to zoledronate. JNJ-28312141 exhibited additional activity against FMS-related receptor tyrosine kinase-3 (FLT3). To more fully define the therapeutic potential of this new agent, JNJ-28312141 was evaluated in a FLT3-dependent acute myeloid leukemia tumor xenograft model and caused tumor regression. In summary, this novel CSF-1R/FLT3 inhibitor represents a new agent with potential therapeutic activity in acute myeloid leukemia and in settings where CSF-1-dependent macrophages and osteoclasts contribute to tumor growth and skeletal events.
Assuntos
Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/secundário , Imidazóis/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Piperidinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Animais , Neoplasias Ósseas/enzimologia , Neoplasias Ósseas/patologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Humanos , Imuno-Histoquímica , Leucemia Mieloide Aguda/enzimologia , Leucemia Mieloide Aguda/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/enzimologia , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Nus , Osteoclastos/efeitos dos fármacos , Osteoclastos/patologia , Ratos , Ratos Sprague-Dawley , Receptor de Fator Estimulador de Colônias de Macrófagos/sangue , Receptor de Fator Estimulador de Colônias de Macrófagos/metabolismo , Especificidade por Substrato , Ensaios Antitumorais Modelo de Xenoenxerto , Tirosina Quinase 3 Semelhante a fms/metabolismoRESUMO
A series of novel potent benzimidazole based inhibitors of interleukin-2 T-cell kinase (Itk) were prepared. In this report, we discuss the structure-activity relationship (SAR), selectivity, and cell-based activity for the series. We also discuss the SAR associated with an X-ray structure of one of the small-molecule inhibitors bound to ITK.
Assuntos
Amidas/química , Benzimidazóis/química , Ácidos Carboxílicos/química , Química Farmacêutica/métodos , Inibidores Enzimáticos/síntese química , Microssomos Hepáticos/metabolismo , Proteínas Tirosina Quinases/química , Animais , Benzimidazóis/síntese química , Ácidos Carboxílicos/síntese química , Cristalografia por Raios X , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Concentração Inibidora 50 , Camundongos , Modelos Químicos , Conformação Molecular , Relação Estrutura-AtividadeRESUMO
An anti-inflammatory 1,2,4-phenylenetriamine-containing series of FMS inhibitors with a potential to form reactive metabolites was transformed into a series with equivalent potency by incorporation of carbon-based replacement groups. Structure-based modeling provided the framework to efficiently effect this transformation and restore potencies to previous levels. This optimization removed a risk factor for potential idiosyncratic drug reactions.
Assuntos
Anti-Inflamatórios/farmacologia , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Fenilenodiaminas/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/química , Simulação por Computador , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Ligação de Hidrogênio , Concentração Inibidora 50 , Modelos Moleculares , Estrutura Molecular , Fenilenodiaminas/síntese química , Fenilenodiaminas/química , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
2-Cyano-6-fluorophenylacetamide was explored as a novel P2 scaffold in the design of thrombin inhibitors. Optimization around this structural motif culminated in 14, which is a potent thrombin inhibitor (K(i)=1.2nM) that exhibits robust efficacy in canine anticoagulation and thrombosis models upon oral administration.
Assuntos
Acetamidas , Motivos de Aminoácidos , Anticoagulantes/administração & dosagem , Desenho de Fármacos , Nitrilas , Trombina/antagonistas & inibidores , Trombose/tratamento farmacológico , Acetamidas/síntese química , Acetamidas/farmacocinética , Acetamidas/uso terapêutico , Administração Oral , Animais , Anticoagulantes/síntese química , Anticoagulantes/farmacocinética , Sítios de Ligação , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Haplorrinos , Humanos , Ligação de Hidrogênio , Modelos Químicos , Nitrilas/síntese química , Nitrilas/farmacocinética , Nitrilas/uso terapêutico , Ratos , Relação Estrutura-AtividadeRESUMO
A series of novel acylsulfonamide, acylsulfamide, and sulfonylurea bioisosteres of carboxylic acids were prepared as CXCR2 antagonists. Structure-activity relationships are reported for these series. One potent orally bioavailable inhibitor had excellent PK properties and was active in a lung injury model in hyperoxia-exposed newborn rats.
Assuntos
Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacologia , Pulmão/efeitos dos fármacos , Receptores de Interleucina-8B/antagonistas & inibidores , Sulfonamidas/química , Ácidos Sulfônicos/química , Compostos de Sulfonilureia/química , Administração Oral , Animais , Animais Recém-Nascidos , Disponibilidade Biológica , Lavagem Broncoalveolar , Ácidos Carboxílicos/farmacocinética , Quimiotaxia/efeitos dos fármacos , Sistema Enzimático do Citocromo P-450/metabolismo , Humanos , Hiperóxia , Pulmão/metabolismo , Lesão Pulmonar , Estrutura Molecular , Neutrófilos/metabolismo , Coelhos , Ratos , Relação Estrutura-AtividadeRESUMO
A series of 3,4,6-substituted 2-quinolones has been synthesized and evaluated as inhibitors of the kinase domain of macrophage colony-stimulating factor-1 receptor (FMS). The fully optimized compound, 4-(4-ethyl-phenyl)-3-(2-methyl-3H-imidazol-4-yl)-2-quinolone-6-carbonitrile 21b, has an IC(50) of 2.5 nM in an in vitro assay and 5.0 nM in a bone marrow-derived macrophage cellular assay. Inhibition of FMS signaling in vivo was also demonstrated in a mouse pharmacodynamic model.
Assuntos
Macrófagos/efeitos dos fármacos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Quinolonas/síntese química , Quinolonas/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Administração Oral , Animais , Disponibilidade Biológica , Proliferação de Células/efeitos dos fármacos , Polarização de Fluorescência , Genes fos/genética , Fator Estimulador de Colônias de Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , Quinolonas/farmacocinética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Receptor de Fator Estimulador de Colônias de Macrófagos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Baço/metabolismo , Relação Estrutura-AtividadeRESUMO
The pharmacokinetics of TDP223206 was studied following single intravenous and oral administrations in rats. A mixture of TDP223206 and (14)C-TDP223206 were administered to intact and bile duct-cannulated rats. Following intravenous administration, plasma concentrations declined biphasically. The AUC(inf) increased linearly with dose but was not dose proportional. The PK parameters of TDP223206 indicated low clearance (254-386 ml/h/kg) and a moderate volume of distribution (968-1883 ml/kg). The bioavailability was 32.95% and 24.46% for 10 and 50 mg/kg oral doses, respectively. (14)C-TDP223206 was distributed widely into different tissues with small intestine, liver, kidneys and large intestine having large tissue to plasma ratios. (14)C-TDP223206 was the major circulating component in the plasma. A total of 91.2% of administered radioactivity of (14)C-TDP223206 was recovered in bile indicating that biliary excretion was the major pathway for drug elimination. (14)C-TDP223206-acyl glucuronides were the major metabolites in bile. The oxo-(14)C-TDP223206 was the major metabolite in plasma and an important metabolite in bile. Two forms of diastereomeric acyl glucuronides of (14)C-TDP223206 were detected in bile with similar LC/MS intensities suggesting a similar biotransformation capacity. Only one form of these (14)C-TDP223206-acyl glucuronides was detected in plasma suggesting that enterohepatic recirculation was related to the nature of the stereo-isomers.
Assuntos
Indóis/farmacocinética , Integrina alfaVbeta3/antagonistas & inibidores , Propionatos/farmacocinética , Administração Oral , Animais , Bile/metabolismo , Fezes/química , Indóis/sangue , Indóis/urina , Injeções Intravenosas , Masculino , Propionatos/administração & dosagem , Propionatos/sangue , Propionatos/urina , Ratos , Ratos Sprague-Dawley , Distribuição TecidualRESUMO
Complement activation has been implicated in disease states such as hereditary angioedema, ischemia-reperfusion injury, acute respiratory distress syndrome, and acute transplant rejection. Even though the complement cascade provides several protein targets for potential therapeutic intervention only two complement inhibitors have been approved so far for clinical use including anti-C5 antibodies for the treatment of paroxysmal nocturnal hemoglobinuria and purified C1-esterase inhibitor replacement therapy for the control of hereditary angioedema flares. In the present study, optimization of potency and physicochemical properties of a series of thiophene amidine-based C1s inhibitors with potential utility as intravenous agents for the inhibition of the classical pathway of complement is described.
Assuntos
Complemento C1s/antagonistas & inibidores , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Animais , Sítios de Ligação , Meia-Vida , Modelos Moleculares , Estrutura Molecular , Ratos , Relação Estrutura-AtividadeRESUMO
The optimization of the arylamide lead 2 resulted in identification of a highly potent series of 2,4-disubstituted arylamides. Compound 8 (FMS kinase IC(50)=0.0008 microM) served as a proof-of-concept candidate in a collagen-induced model of arthritis in mice.
Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/antagonistas & inibidores , Animais , Artrite/induzido quimicamente , Artrite/tratamento farmacológico , Colágeno , Relação Dose-Resposta a Droga , Camundongos , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Fatores de TempoRESUMO
The pharmacokinetics of TDP4815 was evaluated in rats, rabbits, dogs and monkeys. After intravenous administration, TDP4815 achieved C(O) of 3255 ng/ml in rats at 5 mg/kg, 9066 ng/ml in rabbits and 7858 ng/ml in monkeys at 6 mg/kg, and 4457 ng/ml in dogs at 3 mg/kg. The clearance (C(L)) was 3105, 1692, 835 and 640 ml/h/kg in rats, rabbits, monkeys and dogs, respectively. The volume of distribution (V(Z)) was more than 3861 ml/kg in all species, except 1915 ml/kg in monkeys. The oral bioavailability was rabbit >rat> monkey compared at 100 mg/kg, but it was much higher in dogs (>64%) after oral administrations. The calculated intrinsic clearance data suggested that the clearance of dog and human was restricted by binding to the plasma protein, and the clearance of rat and monkey was dependent on both the free fraction of plasma protein binding and the liver blood flow rate. The unbound hepatic intrinsic clearance of monkey was close to its C(L) suggesting that the hepatic clearance was an important excretion in monkeys. The poor oral bioavailability in the monkey may be related to the extensive glucuronidation. The V(Z).kg and C(L).kg in test species showed good correlation with the animal body weights (R(2)=0.87 and 0.96).
Assuntos
Anticoagulantes/farmacocinética , Guanidina/análogos & derivados , Administração Oral , Animais , Anticoagulantes/administração & dosagem , Disponibilidade Biológica , Peso Corporal , Cães , Glucuronídeos/metabolismo , Guanidina/administração & dosagem , Guanidina/farmacocinética , Humanos , Técnicas In Vitro , Injeções Intravenosas , Fígado/irrigação sanguínea , Fígado/metabolismo , Macaca fascicularis , Masculino , Microssomos Hepáticos/metabolismo , Ligação Proteica , Coelhos , Ratos , Ratos Sprague-Dawley , Especificidade da Espécie , Distribuição TecidualRESUMO
2-(2-Chloro-6-fluorophenyl)acetamides having 2,2-difluoro-2-aryl/heteroaryl-ethylamine P3 and oxyguanidine P1 substituents are potent thrombin inhibitors (K(i)=0.9-33.9 nM). 2-(5-Chloro-pyridin-2-yl)-2,2-difluoroethylamine was the best P3 substituent, yielding the most potent inhibitor (K(i)=0.7 nM). Replacing the P3 heteroaryl group with a phenyl ring or replacing the difluoro substitution with dimethyl or cyclopropyl groups in the linker reduced the affinity for thrombin significantly. The aminopyridine P1s also provided an increase in potency.
Assuntos
Acetamidas/síntese química , Acetamidas/farmacologia , Anticoagulantes/síntese química , Anticoagulantes/farmacologia , Hidrocarbonetos Halogenados/síntese química , Hidrocarbonetos Halogenados/farmacologia , Trombina/antagonistas & inibidores , Acetamidas/química , Anticoagulantes/química , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Humanos , Hidrocarbonetos Halogenados/química , Estrutura Molecular , Relação Estrutura-Atividade , Trombina/químicaRESUMO
The vitronectin receptor alpha(v)beta(3) has been identified as a promising potential target for the treatment of osteoporosis, diabetic retinopathy and cancer. We have recently reported 5-substituted indoles 3-[5-[2-(5,6,7,8-tetrahydro[1,8]naphthyridin-2-yl)ethoxy]indol-1-yl]-3-(3-pyridyl)propionic acid 3 and 3-[5-[2-(5,6,7,8-tetrahydro[1,8]naphthyridin-2-yl)ethoxy]indol-1-yl]-3-(3,4-methylenedioxyphenyl)propionic acid 4, as an original series of potent alpha(v)beta(3) antagonists with subnanomolar activity. Ligand-protein docking analyses have been performed to generate binding models of three different chemical classes of known alpha(v)beta(3) antagonists with alpha(v)beta(3). Results of this docking study suggested that indoles bearing the basic tetrahydronaphthyridine group at position 4 can easily adopt the correct binding conformation and should be as potent as our current 5-substituted indole leads 3 and 4. This hypothesis was nicely demonstrated by the synthesis of a series of 1,4-disubstituted indoles through a tandem of reactions involving: (i) the N-alkylation of indoles 15 and 22 with propargyl esters and cesium fluoride, and (ii) a Heck coupling reaction between 4-bromoindole and 7-vinyl-3,4-dihydro-2H-[1,8]naphthyridine-1-carboxylic acid tert-butyl ester 12, or (iii) a reductive amination involving the N-substituted-4-aminoindole 23 and the BOC-protected tetrahydro[1,8]naphthyridine aldehyde 13. Among the compounds assayed, 3-(3-pyridyl)-3-[4-[2-(5,6,7,8-tetrahydro[1,8]naphthyridin-2-yl)ethyl]indol-1-yl]propionic acid 21 showed the most promising activity on alpha(v)beta(3) (IC(50)=0.5 nM), and was found to have the same potency as our current leads 3 and 4, while maintaining selectivity over alpha(IIb)beta(IIIa). Moreover, based on the reasonable apparent permeability coefficient in an in vitro CACO-2 cell monolayer assay (P(app) apical/basolateral=2.2 x 10(-6)cm/s, P(app) basolateral/apical=2.5 x 10(-6)cm/s), compound 21 is expected to be absorbed through the intestine in human. Thus, 1,4-disubstituted indole 21 represents a new lead for this novel class of conformationally restricted alpha(v)beta(3) antagonists. Additionally, this study validates the pharmacophore model previously postulated and provides an improved basis for further structure-based drug design in the field of alpha(v)beta(3).
Assuntos
Indóis/síntese química , Indóis/farmacologia , Integrina alfaVbeta3/antagonistas & inibidores , Desenho de Fármacos , Ensaio de Imunoadsorção Enzimática , Humanos , Indicadores e Reagentes , Indóis/química , Integrina alfa5beta1/antagonistas & inibidores , Integrinas/antagonistas & inibidores , Ligantes , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Glicoproteína IIb da Membrana de Plaquetas/efeitos dos fármacos , Receptores de Vitronectina/antagonistas & inibidores , Relação Estrutura-Atividade , Difração de Raios XRESUMO
The binding of lead compounds and drugs to human serum albumin (HSA) is a ubiquitous problem in drug discovery since it modulates the availability of the leads and drugs to their intended target, which is linked to biological efficacy. In our continuing efforts to identify small molecule alpha(V)beta(3) and alpha(V)beta(5) dual antagonists, we recently reported indoles 2-4 as potent and selective alpha(V)beta(3)/alpha(V)beta(5) antagonists with good oral bioavailability profile. In spite of subnanomolar binding affinity of these compounds to human alpha(V)beta(3) and alpha(V)beta(5) integrins, high HSA binding (96.5-97.3%) emerged as a limiting feature for these leads. Structure-activity HSA binding data of organic acids reported in the literature have demonstrated that the incorporation of polar groups into a given molecule can dramatically decrease the affinity toward HSA. We sought to apply this strategy by examining the effects of such modifications in both the central core constrain and the substituent beta to the carboxylate. Most of these derivatives were prepared in good yields through a cesium fluoride-catalyzed coupling reaction. This reaction was successful with a variety of nitrogen-containing scaffolds (20, 33, and 43) and selected acetylenic derivatives (16, 19, and 34). Among the compounds synthesized, the 3-[5-[2-(5,6,7,8-tetrahydro [1,8]naphthyridin-2-yl)ethoxy]indol-1-yl]-3-[5-(N,N-dimethylaminomethyl)-3-pyridyl]propionic acid (25) was found to be the most promising derivative within this novel series with a subnanomolar affinity for both alpha(v)beta(3) and alpha(v)beta(5) (IC(50) = 0.29 and 0.16 nM, respectively), similar to our initial lead receptor antagonists 2-4, and exhibiting a low HSA protein binding (40% bound, K(d) = 1.1+/-0.4 x 10(3) microM) and an improved in vitro stability profile toward human and mouse microsomes (99.9% and 98.7% remaining after 10 min). Moreover, the selectivity of 25 toward alpha(5)beta(1) and IIbIIIa integrins was perfectly maintained when compared to the parent leads 2-4. Thus, compound 25 was selected as a new lead with improved drug-like properties for further evaluations in the field of oncology and osteoporosis.