RESUMO
BACKGROUND: Apixaban is an oral, direct and highly selective factor Xa (FXa) inhibitor in late-stage clinical development for the prevention and treatment of thromboembolic diseases. OBJECTIVE: We evaluated the in vitro properties of apixaban and its in vivo activities in rabbit models of thrombosis and hemostasis. METHODS: Studies were conducted in arteriovenous-shunt thrombosis (AVST), venous thrombosis (VT), electrically mediated carotid arterial thrombosis (ECAT) and cuticle bleeding time (BT) models. RESULTS: In vitro, apixaban is potent and selective, with a K(i) of 0.08 nm for human FXa. It exhibited species difference in FXa inhibition [FXa K(i) (nm): 0.16, rabbit; 1.3, rat; 1.7, dog] and anticoagulation [EC(2x) (microm, concentration required to double the prothrombin time): 3.6, human; 2.3, rabbit; 7.9, rat; 6.7, dog]. Apixaban at 10 microm did not alter human and rabbit platelet aggregation to ADP, gamma-thrombin, and collagen. In vivo, the values for antithrombotic ED(50) (dose that reduced thrombus weight or increased blood flow by 50% of the control) in AVST, VT and ECAT and the values for BT ED(3x) (dose that increased BT by 3-fold) were 0.27 +/- 0.03, 0.11 +/- 0.03, 0.07 +/- 0.02 and > 3 mg kg(-1) h(-1) i.v. for apixaban, 0.05 +/- 0.01, 0.05 +/- 0.01, 0.27 +/- 0.08 and > 3 mg kg(-1) h(-1) i.v. for the indirect FXa inhibitor fondaparinux, and 0.53 +/- 0.04, 0.27 +/- 0.01, 0.08 +/- 0.01 and 0.70 +/- 0.07 mg kg(-1) day(-1) p.o. for the oral anticoagulant warfarin, respectively. CONCLUSIONS: In summary, apixaban was effective in the prevention of experimental thrombosis at doses that preserve hemostasis in rabbits.
Assuntos
Pirazóis/farmacologia , Piridonas/farmacologia , Trombose/tratamento farmacológico , Animais , Trombose das Artérias Carótidas , Modelos Animais de Doenças , Cães , Inibidores do Fator Xa , Hemostasia/efeitos dos fármacos , Humanos , Agregação Plaquetária/efeitos dos fármacos , Pirazóis/administração & dosagem , Piridonas/administração & dosagem , Coelhos , Ratos , Trombose/prevenção & controle , Trombose VenosaRESUMO
A pharmacophore model of the P1' site, specific for aggrecanase, was defined using the specificity studies of the matrix metalloproteinases and the similar biological activity of aggrecanase and MMP-8. Incorporation of the side chain of a tyrosine residue into compound 1 as the P1' group provided modest selectivity for aggrecanase over MMP-1, -2, and -9. A cis-(1S)(2R)-amino-2-indanol scaffold was incorporated as a tyrosine mimic (P2') to conformationally constrain 2. Further optimization resulted in compound 11, a potent, selective, and orally bioavailable inhibitor of aggrecanase.
Assuntos
Asparagina/síntese química , Endopeptidases/metabolismo , Ácidos Hidroxâmicos/síntese química , Inibidores de Proteases/síntese química , Administração Oral , Animais , Asparagina/análogos & derivados , Asparagina/química , Asparagina/farmacocinética , Asparagina/farmacologia , Disponibilidade Biológica , Cães , Desenho de Fármacos , Endopeptidases/química , Ácidos Hidroxâmicos/química , Ácidos Hidroxâmicos/farmacocinética , Ácidos Hidroxâmicos/farmacologia , Metaloproteinase 1 da Matriz/química , Metaloproteinase 2 da Matriz/química , Metaloproteinase 8 da Matriz/química , Metaloproteinase 9 da Matriz/química , Modelos Moleculares , Inibidores de Proteases/química , Inibidores de Proteases/farmacocinética , Inibidores de Proteases/farmacologia , Ligação Proteica , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
SAR exploration at P1' using an anti-succinate-based macrocyclic hydroxamic acid as a template led to the identification of several bulky biphenylmethyl P1' derivatives which confer potent porcine TACE and anti-TNF-alpha cellular activities with high selectivity versus most of the MMPs screened. Our studies demonstrate for the first time that TACE has a larger S1' pocket in comparison to MMPs and that potent and selective TACE inhibitors can be achieved by incorporation of sterically bulky P1' residues.
Assuntos
Compostos Heterocíclicos com 1 Anel/síntese química , Ácidos Hidroxâmicos/síntese química , Metaloendopeptidases/antagonistas & inibidores , Inibidores de Proteases/síntese química , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Proteínas ADAM , Proteína ADAM17 , Sítios de Ligação , Compostos Heterocíclicos com 1 Anel/química , Compostos Heterocíclicos com 1 Anel/farmacologia , Humanos , Ácidos Hidroxâmicos/química , Ácidos Hidroxâmicos/farmacologia , Lipopolissacarídeos/farmacologia , Modelos Moleculares , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Ligação Proteica , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Selective antagonism of the platelet GPIIb/IIIa receptor represents an attractive mechanism for the prevention and treatment of a number of thrombotic disease states. The antiplatelet activity of the oral GPIIb/IIIa receptor antagonists DMP 754 and DMP 802 have been disclosed. In this paper, the synthesis and biological evaluation of a series of potent N-substituted benzamidine isoxazolines are explored. The effect of benzamidine substitution on the duration of antiplatelet efficacy in dog is presented.
Assuntos
Isoxazóis/síntese química , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Aminoácidos/química , Aminoácidos/farmacologia , Isoxazóis/química , Isoxazóis/farmacologia , Inibidores da Agregação Plaquetária/química , Inibidores da Agregação Plaquetária/farmacologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacologiaRESUMO
To search for TNF-alpha (tumor necrosis factor alpha) converting enzyme (TACE) inhibitors, we designed a new class of macrocyclic hydroxamic acids by linking the P1 and P2' residues of acyclic anti-succinate-based hydroxamic acids. A variety of residues including amide, carbamate, alkyl, sulfonamido, Boc-amino, and amino were found to be suitable P1-P2' linkers. With an N-methylamide at P3', the 13-16-membered macrocycles prepared exhibited low micromolar activities in the inhibition of TNF-alpha release from LPS-stimulated human whole blood. Further elaboration in the P3'-P4' area using the cyclophane and cyclic carbamate templates led to the identification of a number of potent analogues with IC(50) values of =0.2 microM in whole blood assay (WBA). Although the P3' area can accommodate a broad array of structurally diversified functional groups including polar residues, hydrophobic residues, and amino and carboxylic acid moieties, in both the cyclophane series and the cyclic carbamate series, a glycine residue at P3' was identified as a critical structural component to achieve both good in vitro potency and good oral activity. With a glycine residue at P3', an N-methylamide at P4' provided the best cyclophane analogue, SL422 (WBA IC(50) = 0.22 microM, LPS-mouse ED(50) = 15 mg/kg, po), whereas a morpholinylamide at P4' afforded the most potent and most orally active cyclic carbamate analogue, SP057 (WBA IC(50) = 0.067 microM, LPS-mouse ED(50) = 2.3 mg/kg, po). Further profiling for SL422 and SP057 showed that these macrocyclic compounds are potent TACE inhibitors, with K(i) values of 12 and 4.2 nM in the porcine TACE assay, and are broad-spectrum MMP inhibitors. Pharmacokinetic studies in beagle dogs revealed that SL422 and SP057 are orally bioavailable, with oral bioavailabilities of 11% and 23%, respectively.
Assuntos
Inibidores Enzimáticos/síntese química , Ácidos Hidroxâmicos/síntese química , Lactamas/síntese química , Metaloendopeptidases/antagonistas & inibidores , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Proteínas ADAM , Proteína ADAM17 , Administração Oral , Animais , Disponibilidade Biológica , Carbamatos/síntese química , Carbamatos/química , Carbamatos/farmacocinética , Carbamatos/farmacologia , Cães , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/farmacologia , Humanos , Ácidos Hidroxâmicos/química , Ácidos Hidroxâmicos/farmacocinética , Ácidos Hidroxâmicos/farmacologia , Técnicas In Vitro , Lactamas/química , Lactamas/farmacocinética , Lactamas/farmacologia , Masculino , Camundongos , Estereoisomerismo , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/análiseRESUMO
The selective inhibition of coagulation factor Xa has emerged as an attractive strategy for the discovery of novel antithrombotic agents. Here we describe highly potent benzamidine factor Xa inhibitors based on a vicinally-substituted heterocyclic core.
Assuntos
Benzamidinas/química , Benzamidinas/farmacologia , Inibidores do Fator Xa , Compostos Heterocíclicos/química , Inibidores de Serina Proteinase/química , Animais , Benzamidinas/síntese química , Compostos Heterocíclicos/síntese química , Humanos , Cinética , Estrutura Molecular , Coelhos , Inibidores de Serina Proteinase/síntese química , Inibidores de Serina Proteinase/farmacologia , Relação Estrutura-AtividadeRESUMO
Factor Xa (fXa) plays a critical role in the coagulation cascade, serving as the point of convergence of the intrinsic and extrinsic pathways. Together with nonenzymatic cofactor Va and Ca2+ on the phospholipid surface of platelets or endothelial cells, factor Xa forms the prothrombinase complex, which is responsible for the proteolysis of prothrombin to catalytically active thrombin. Thrombin, in turn, catalyzes the cleavage of fibrinogen to fibrin, thus initiating a process that ultimately leads to clot formation. Recently, we reported on a series of isoxazoline and isoxazole monobasic noncovalent inhibitors of factor Xa which show good potency in animal models of thrombosis. In this paper, we wish to report on the optimization of the heterocyclic core, which ultimately led to the discovery of a novel pyrazole SN429 (2b; fXa K(i) = 13 pM). We also report on our efforts to improve the oral bioavailability and pharmacokinetic profile of this series while maintaining subnanomolar potency and in vitro selectivity. This was achieved by replacing the highly basic benzamidine P1 with a less basic benzylamine moiety. Further optimization of the pyrazole core substitution and the biphenyl P4 culminated in the discovery of DPC423 (17h), a highly potent, selective, and orally active factor Xa inhibitor which was chosen for clinical development.
Assuntos
Inibidores do Fator Xa , Fibrinolíticos/síntese química , Pirazóis/síntese química , Inibidores de Serina Proteinase/síntese química , Sulfonas/síntese química , Administração Oral , Animais , Disponibilidade Biológica , Cristalografia por Raios X , Cães , Fibrinolíticos/química , Fibrinolíticos/farmacocinética , Fibrinolíticos/farmacologia , Modelos Moleculares , Pirazóis/química , Pirazóis/farmacocinética , Pirazóis/farmacologia , Ratos , Inibidores de Serina Proteinase/química , Inibidores de Serina Proteinase/farmacocinética , Inibidores de Serina Proteinase/farmacologia , Relação Estrutura-Atividade , Sulfonas/química , Sulfonas/farmacocinética , Sulfonas/farmacologiaRESUMO
Thrombosis is a major cause of mortality in the industrialized world. Therefore, the control of blood coagulation has become a major target for new therapeutic agents. One attractive approach is the inhibition of factor Xa (fXa), the enzyme directly responsible for thrombin generation. In this review we describe our approaches in the design and synthesis of small molecule, noncovalent fXa inhibitors. Rational drug design and selective screening of our GPIIb/IIIa library afforded several lead compounds for our fXa program. Following-up the leads in the isoxazoline series led to potent fXa inhibitors such as SF303 and SK509 with only one basic group. The isoxazole series was then designed to remove the chiral center in the isoxazoline ring, and this effort led to SA862 which has subnanomolar fXa affinity. Optimizing the core structure generated a series of novel five-membered ring heterocycles substituted with benzamidine, which are potent fXa inhibitors. Further optimization in the pyrazole series resulted in the discovery of fXa inhibitors such as SN429 with picomolar fXa affinity. Efforts to improve the oral bioavailability by lowering the basicity of these compounds, while simultaneously maintaining potency against fXa, culminated in the discovery of DPC 423. DPC 423 was selected for clinical evaluation as a potent and orally bioavailable fXa inhibitor.
Assuntos
Inibidores do Fator Xa , Fibrinolíticos/síntese química , Pirazóis/síntese química , Sulfonas/síntese química , Animais , Disponibilidade Biológica , Cães , Desenho de Fármacos , Fibrinolíticos/química , Fibrinolíticos/farmacologia , Meia-Vida , Humanos , Concentração Inibidora 50 , Tempo de Protrombina , Pirazóis/química , Pirazóis/farmacologia , Coelhos , Sulfonas/química , Sulfonas/farmacologiaRESUMO
Thrombotic diseases are a major cause of death and morbidity. Factor Xa (fXa) plays a vital role in the regulation of normal homeostasis and abnormal intravascular thrombus development in the blood coagulation cascade. A novel series of fXa inhibitors incorporating an amidino 6,5-fused bicyclic moiety at the P1 position has been designed and synthesized based on molecular modeling studies. Structure-activity relationship (SAR) studies have led to selective subnanomolar fXa inhibitors. The most potent fXa inhibitor in this series (72, SE170) has a potent inhibition constant (K(i) = 0.3 nM), is 350-fold selective for fXa over trypsin, and also shows good in vivo efficacy in a rabbit arterio-venous thrombosis model (ID(50) = 0.14 micromol/kg/h). An X-ray crystal structure of 72 complexed to bovine trypsin was completed, and a binding mode of 72 with fXa has been proposed based on modeling with human des-Gla-fXa.
Assuntos
Amidinas/síntese química , Benzimidazóis/síntese química , Inibidores do Fator Xa , Fibrinolíticos/síntese química , Indazóis/síntese química , Indóis/síntese química , Sulfonamidas/síntese química , Amidinas/química , Amidinas/farmacocinética , Amidinas/farmacologia , Animais , Benzimidazóis/química , Benzimidazóis/farmacocinética , Benzimidazóis/farmacologia , Bovinos , Cristalografia por Raios X , Cães , Desenho de Fármacos , Fibrinolíticos/química , Fibrinolíticos/farmacocinética , Fibrinolíticos/farmacologia , Humanos , Indazóis/química , Indazóis/farmacocinética , Indazóis/farmacologia , Indóis/química , Indóis/farmacocinética , Indóis/farmacologia , Modelos Moleculares , Coelhos , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacocinética , Sulfonamidas/farmacologia , Tripsina/química , Trombose Venosa/tratamento farmacológicoRESUMO
SK549 (mol. wt. 546 Da) is a synthetic, selective inhibitor of human coagulation factor Xa (fXa) (K(i) = 0.52 nM). This study compared the antithrombotic effects of SK549 and a series of benzamidine isoxazoline fXa inhibitors with aspirin, DuP 714 (a direct thrombin inhibitor), recombinant tick anticoagulant peptide, or heparin in a rabbit model of electrically induced carotid arterial thrombosis. Compounds were infused i.v. continuously from 60 min before electrical stimulation to the end of the experiment. Values of ED(50) (dose that increases the carotid blood flow to 50% of the control) were 0.12 micromol/kg/h for SK549, 0.56 micromol/kg/h for aspirin, 0.14 micromol/kg/h for DuP 714, 0.06 micromol/kg/h for recombinant tick anticoagulant peptide, and >100 U/kg/h for heparin. The EC(50) (plasma concentration that increased blood flow to 50% of the control) for SK549 was 97 nM. Unlike aspirin and heparin, SK549 was efficacious and, at 1.5 micromol/kg/h i.v. (n = 9), maintained carotid blood flow at 87 +/- 6% of control level for greater than 90 min. Unlike heparin, SK549 inhibited ex vivo fXa activity but not ex vivo thrombin activity. There was a highly significant correlation between K(i) (fXa) and ED(50) of a series of fXa inhibitors (r = 0. 85, P <.001). Therefore, these results suggest that SK549 is a novel, potent, and effective antithrombotic agent in a rabbit model of arterial thrombosis. It is likely that SK549 exerts its antithrombotic effect through selective inhibition of fXa. Furthermore, SK549 may be clinically useful for the prevention of arterial thrombosis.
Assuntos
Trombose das Artérias Carótidas/tratamento farmacológico , Inibidores do Fator Xa , Fibrinolíticos/uso terapêutico , Isoxazóis/uso terapêutico , Tetrazóis/uso terapêutico , Animais , Aspirina/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Compostos de Boro/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Heparina/farmacologia , Humanos , Isoxazóis/farmacologia , Masculino , Microscopia Eletrônica de Varredura , Oligopeptídeos/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Coelhos , Proteínas Recombinantes/farmacologia , Tetrazóis/farmacologiaRESUMO
Conformationally restricted borolysine compounds containing a 2-(2-cyanophenylthio) benzoyl in the P3 position unexpectedly led to enhanced factor Xa inhibition. In an effort to improve both the potency and selectivity of this series by extending into the S' domain, we have replaced the boronic acid with alpha-ketoamides, utilizing a novel process that was developed in our labs.
Assuntos
Amidas/síntese química , Amidas/farmacologia , Inibidores do Fator Xa , Inibidores de Serina Proteinase/síntese química , Inibidores de Serina Proteinase/farmacologia , Amidas/química , Modelos Moleculares , Inibidores de Serina Proteinase/química , Relação Estrutura-AtividadeRESUMO
3,4,5-Trisubstituted isoxazolines (2) and isoxazoles (3) were prepared and evaluated for their in vitro and in vivo antithrombotic efficacy. They were compared to 3,5,5-trisubstituted isoxazolines (1) for Factor Xa selectivity and potency. They were also compared in an arterio-venous (A-V) shunt model of thrombosis.
Assuntos
Inibidores do Fator Xa , Isoxazóis/farmacologia , Inibidores de Serina Proteinase/farmacologia , Animais , Cristalografia por Raios X , Isoxazóis/química , Isoxazóis/farmacocinética , Modelos Moleculares , Coelhos , Inibidores de Serina Proteinase/química , Inibidores de Serina Proteinase/farmacocinética , Relação Estrutura-Atividade , Trombose/prevenção & controleRESUMO
A series of ring constrained analogues of the GPIIb/IIIa receptor antagonist XR299 (1) was investigated as potential inhibitors of glycoprotein IIb/IIIa, a platelet receptor that plays a key role in platelet aggregation and platelet adhesion. Ring size was found to have a large effect on in vitro potency. Selected compounds showed good in vitro activity, a preference for binding to activated platelets, and modest duration of action when dosed i.v. as a racemate in a canine model.
Assuntos
Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , beta-Alanina/química , beta-Alanina/farmacologia , Humanos , Técnicas In Vitro , Isoxazóis/química , Isoxazóis/farmacologia , Conformação Molecular , Nitrogênio/química , Adesividade Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/síntese química , Inibidores da Agregação Plaquetária/farmacologiaRESUMO
In this report refinements to the S4 ligand group leads to compound 19, an inhibitor of fXa with good potency in vitro and an improved pharmacokinetic profile in rabbit. The X-ray crystallographic study of a representative analogue confirms our binding model for this series.
Assuntos
Inibidores do Fator Xa , Inibidores de Serina Proteinase/síntese química , Ureia/síntese química , Animais , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Coelhos , Inibidores de Serina Proteinase/farmacocinética , Inibidores de Serina Proteinase/farmacologia , Ureia/farmacocinética , Ureia/farmacologiaRESUMO
Starting with lead compound 2, we sought to increase the selectivity for alpha(v)beta(3)-mediated cell adhesion by examining the effects of structural changes in both the guanidine mimetic and the substituent alpha to the carboxylate. To prepare some of the desired aminoimidazoles, a novel reductive amination utilizing a trityl-protected aminoimidazole was developed. It was found that guanidine mimetics with a wide range of pK(a)'s were potent antagonists of alpha(v)beta(3). In general, it appeared that an acylated 2-aminoimidazole guanidine mimetic imparted excellent selectivity for alpha(v)beta(3)-mediated adhesion versus alpha(IIb)beta(3)-mediated platelet aggregation, with selectivity of approximately 3 orders of magnitude observed for compounds 3g and 3h. It was also found in this series that the alpha-substituent was required for potent activity and that 2,6-disubstituted arylsulfonamides were optimal. In addition, the selective alpha(v)beta(3) antagonist 3h was found to be a potent inhibitor of alpha(v)beta(3)-mediated cell migration.
Assuntos
Isoxazóis/síntese química , Receptores de Vitronectina/antagonistas & inibidores , beta-Alanina/análogos & derivados , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Guanidinas/química , Humanos , Hiperplasia/metabolismo , Técnicas In Vitro , Isoxazóis/química , Isoxazóis/farmacologia , Rim/citologia , Rim/efeitos dos fármacos , Rim/metabolismo , Agregação Plaquetária/efeitos dos fármacos , Receptores de Vitronectina/biossíntese , Estereoisomerismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Vitronectina/farmacologia , beta-Alanina/síntese química , beta-Alanina/química , beta-Alanina/farmacologiaRESUMO
A new series of indazole-containing alpha(v)beta(3) integrin antagonists is described. Starting with lead compound 18a, variations in a number of structural features were explored with respect to inhibition of the binding of beta(3)-transfected 293 cells to fibrinogen and to selectivity for alpha(v)beta(3) over GPIIbIIIa, another RGD-binding integrin. Indazoles attached to a 2-aminopyridine or 2-aminoimidazole by a propylene linker at the indazole 1-position and to a diaminopropionate derivative via a 5-carboxylate amide provided the best potency with moderate selectivity. Several differences in the SAR of the diaminopropionate moiety were observed between this series and a series of isoxazoline-based selective GPIIbIIIa antagonists. Compound 34a (SM256) was a potent antagonist of alpha(v)beta(3) (IC(50) 2.3 nM) with 9-fold selectivity over GPIIbIIIa.
Assuntos
Indazóis/síntese química , Receptores de Vitronectina/antagonistas & inibidores , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Fibrinogênio/metabolismo , Humanos , Técnicas In Vitro , Indazóis/química , Indazóis/farmacologia , Modelos Moleculares , Agregação Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Relação Estrutura-AtividadeRESUMO
A series of benzamidine isoxazoline derivatives was evaluated for their inhibitory potency against purified human factor Xa (fXa) and in a rabbit model of arteriovenous shunt thrombosis for their antithrombotic activities, expressed as K(I) and IC(50), respectively. A highly significant correlation was found between K(I) and IC(50) (r = 0.93, P <.0001). The antithrombotic effects of SF303 [mol. wt. 536; K(I): fXa, 6.3 nM; thrombin, 3,100 nM; trypsin, 110 nM; tissue plasminogen activator >20,000 nM; plasmin, 2,500 nM] and SK549 [mol. wt. 546; K(I): fXa, 0.52 nM; thrombin, 400 nM; trypsin, 45 nM; tissue plasminogen activator >33,000 nM; plasmin, 890 nM] were compared with recombinant tick anticoagulant peptide [K(I)(fXa) = 0.5 nM], DX-9065a [K(I)(fXa) = 30 nM], and heparin or low molecular weight heparin (dalteparin) in a rabbit model of arteriovenous shunt thrombosis. ID(50) values for preventing arteriovenous shunt-induced thrombosis were 0.6 micromol/kg/h for SF303, 0.035 micromol/kg/h for SK549, 0.01 micromol/kg/h for recombinant tick anticoagulant peptide, 0.4 micromol/kg/h for DX-9065a, 21 U/kg/h for heparin, and 23 U/kg/h for low molecular weight heparin. SK549 produced a concentration-dependent antithrombotic effect with an IC(50) of 0.062 microM. To evaluate its potential oral efficacy, SK549 was given intraduodenally at a dose of 5 mg/kg; it produced a peak antithrombotic effect of 59 +/- 4% with a duration of action greater than 6.7 h. Therefore, our study suggests that SF303, SK549, and their analogs represent a new class of synthetic fXa inhibitors that may be clinically useful as antithrombotic agents.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Inibidores do Fator Xa , Isoxazóis/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Sulfonamidas/farmacologia , Tetrazóis/farmacologia , Trombose/tratamento farmacológico , Animais , Anticoagulantes/farmacologia , Derivação Arteriovenosa Cirúrgica , Dalteparina/farmacologia , Relação Dose-Resposta a Droga , Fibrinolíticos/farmacologia , Fibrinolíticos/uso terapêutico , Heparina/farmacologia , Humanos , Técnicas In Vitro , Isoxazóis/uso terapêutico , Masculino , Naftalenos/farmacologia , Propionatos/farmacologia , Coelhos , Proteínas Recombinantes/farmacologia , Tetrazóis/uso terapêuticoRESUMO
Intravascular clot formation is an important factor in a number of cardiovascular diseases. Therefore, the prevention of blood coagulation has become a major target for new therapeutic agents. One attractive approach is the inhibition of factor Xa (FXa), the enzyme directly responsible for thrombin activation. Herein we report a series of isoxazoline derivatives which are potent FXa inhibitors. Optimization of the side chain at the quaternary position of the isoxazoline ring led to SK549 which showed subnanomolar FXa potency (K(i) 0.52 nM). SK549 shows good selectivity for FXa compared to thrombin and trypsin, potent antithrombotic effect in the rabbit arterio-venous thrombosis model, and improved pharmacokinetics relative to other compounds evaluated from this series.
Assuntos
Inibidores do Fator Xa , Fibrinolíticos/síntese química , Isoxazóis/síntese química , Tetrazóis/síntese química , Animais , Derivação Arteriovenosa Cirúrgica , Sítios de Ligação , Cristalografia por Raios X , Cães , Fibrinolíticos/química , Fibrinolíticos/farmacologia , Humanos , Isoxazóis/química , Isoxazóis/farmacologia , Modelos Moleculares , Coelhos , Relação Estrutura-Atividade , Tetrazóis/química , Tetrazóis/farmacologia , Trombina/antagonistas & inibidores , Trombose/tratamento farmacológico , Tripsina/metabolismo , Inibidores da Tripsina/síntese química , Inibidores da Tripsina/química , Inibidores da Tripsina/farmacocinética , Inibidores da Tripsina/farmacologiaRESUMO
Thrombosis is a major cause of mortality in the industrialized world. Therefore, the prevention of blood coagulation has become a major target for new therapeutic agents. One attractive approach is the inhibition of factor Xa (FXa), the enzyme directly responsible for prothrombin activation. We report a series of novel biaryl-substituted isoxazoline derivatives in which the biaryl moiety was designed to interact with the S(4) aryl-binding domain of the FXa active site. Several of the compounds herein have low nanomolar affinity for FXa, have good in vitro selectivity for FXa, and show potent antithrombotic efficacy in vivo. The three most potent compounds (33, 35, and 37) have inhibition constants for human FXa of 3.9, 2.3, and 0.83 nM, respectively, and ID(50)'s ranging from 0.15 to 0.26 micromol/kg/h in the rabbit arterio-venous thrombosis model.
Assuntos
Acetatos/síntese química , Inibidores do Fator Xa , Fibrinolíticos/síntese química , Isoxazóis/síntese química , Acetatos/química , Acetatos/farmacologia , Animais , Derivação Arteriovenosa Cirúrgica , Sítios de Ligação , Compostos de Bifenilo , Fibrinolíticos/química , Fibrinolíticos/farmacologia , Humanos , Isoxazóis/química , Isoxazóis/farmacologia , Modelos Moleculares , Coelhos , Relação Estrutura-Atividade , Trombose/tratamento farmacológicoRESUMO
The serine protease factor Xa is a critical enzyme in the blood coagulation cascade. Recently, the inhibition of factor Xa has begun to emerge as an attractive strategy for the discovery of novel antithrombotic agents. Here we describe pyrrolidine and isoxazolidine benzamidines as novel and potent inhibitors of factor Xa.