Sulfonamidolactam inhibitors of coagulation factor Xa

Substituent effects of sulfonamide derivatives of metformin that can dually improve cellular glucose utilization and anti-coagulation

Metformin, the most frequently prescribed medicine for the management of type 2 diabetes, has been shown to reduce cardiovascular events in diabetic patients in pre-clinical and clinical studies. The present work reports the design, synthesis, and biological assessment of the impact of six benzenesulfonamide biguanides on various aspects of hemostasis, cell function, red blood cell integrity (RBC), and their ability to uptake glucose in human umbilical endothelial cells (HUVECs). It was found that all synthesized o- and m-benzenesulfonamides, particularly derivatives with nitro (3) and amino groups (4), are characterized by a good safety profile in HUVECs, which was further confirmed in the cellular integrity studies. The biguanide analogues with methoxy group (1, 2) and an amino substituent (5, 6) significantly increased glucose utilization in HUVECs, similarly to the parent drug. Intriguingly, compounds 1, 3, and 6 favourably influenced some of the coagulation parameters. Furthermore, derivative 3 also slowed the process of fibrin polymerization, indicating more beneficial anti-coagulant properties than metformin. None of the novel metformin analogues interact strongly with the erythrocyte lipid-protein bilayer. Our findings indicate that derivative 3 has highly desirable anti-coagulant properties, and compounds 1 and 6 have potential dual-action activity, including anti-hyperglycaemic properties and anti-coagulant activity. As such, these derivatives can be used as lead molecules for further development of anti-diabetic agents with a beneficial effect on hypercoagulability.

The selectivity and bioavailability improvement of novel oral anticoagulants: An overview

Anticoagulants have exhibited a critical role in the prevention and/or treatment of thrombotic diseases. Up to now, kinds of novel oral anticoagulants, inhibiting plasma serine proteases in the coagulation cascade, have been developed to overcome the clinical limitations of classical anticoagulants (like warfarin and heparins). Some of them, such as Apixaban, Rivaroxaban, Edoxaban, and Dabigatran, have been approved by FDA in recent years. This review summarizes the discovery and optimization of representative novel oral anticoagulants with the aim to improve selectivity and bioavailability of compounds. The impact of different targets in the cascade on bleeding risk also is discussed. We hope some more effective, selective, and safer anticoagulants can be developed in the future on the basis of these design experiences.

Synthesis of 3,4-diaminobenzoyl derivatives as factor Xa inhibitors

The coagulation factor Xa (FXa) plays a central role in the blood coagulation cascade. Recent studies have shown that FXa is a particularly attractive target for the development of oral antithrombotic agents. In view of the excellent pharmaceutical properties of 1,2-phenylenediamine-based FXa inhibitors and the reported structure-activity relationship (SAR) analysis of FXa inhibitors, we designed and synthesized a series of 3,4-diaminobenzoyl-based FXa inhibitors. Intensive SAR studies on this new series led to the discovery of 3,4-dimethoxyl substituted compound 7b. 7b is a highly potent, selective, direct FXa inhibitor with excellent in vivo antithrombotic activity.

Potent direct inhibitors of factor Xa based on the tetrahydroisoquinoline scaffold

Direct inhibition of coagulation factor Xa (FXa) carries significant promise for developing effective and safe anticoagulants. Although a large number of FXa inhibitors have been studied, each can be classified as either possessing a highly flexible or a rigid core scaffold. We reasoned that an intermediate level of flexibility will provide high selectivity for FXa considering that its active site is less constrained in comparison to thrombin and more constrained as compared to trypsin. We studied several core scaffolds including 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid for direct FXa inhibition. Using a genetic algorithm-based docking and scoring approach, a promising candidate 23 was identified, synthesized, and found to inhibit FXa with a K(i) of 28 μM. Optimization of derivative 23 resulted in the design of a potent dicarboxamide 47, which displayed a K(i) of 135 nM. Dicarboxamide 47 displayed at least 1852-fold selectivity for FXa inhibition over other coagulation enzymes and doubled PT and aPTT of human plasma at 17.1 μM and 20.2 μM, respectively, which are comparable to those of clinically relevant agents. Dicarboxamide 47 is expected to serve as an excellent lead for further anticoagulant discovery.

Arylsulfonamidopiperidone derivatives as a novel class of factor Xa inhibitors

The design, synthesis and SAR of a novel class of valerolactam-based arylsulfonamides as potent and selective FXa inhibitors is reported. The arylsulfonamide-valerolactam scaffold was derived based on the proposed bioisosterism to the arylcyanoguanidine-caprolactam core in known FXa inhibitors. The SAR study led to compound 46 as the most potent FXa inhibitor in this series, with an IC(50) of 7 nM and EC(2×PT) of 1.7 μM. The X-ray structure of compound 40 bound to FXa shows that the sulfonamide-valerolactam scaffold anchors the aryl group in the S1 and the novel acylcytisine pharmacophore in the S4 pockets.