Effects of some 7-hydroxy coumarin compounds on coagulation factor Xa, urease and antidiabetic enzymes

In this study, a series of eight coumarin-phthalonitrile hybrids (K1-K8), including six novel derivatives, were rationally designed and synthesized via a three-step reaction sequence involving condensation, hydrolyzation, and nucleophilic substitution reactions. The structures of all synthesized derivatives were fully characterized using spectroscopic techniques, including FT-IR, ¹H NMR, ¹³C NMR, and MALDI-TOF-MS, confirming their successful formation and structural integrity. To evaluate their pharmacological potential, the synthesized compounds were subjected to comprehensive in vitro enzyme inhibition assays targeting α-amylase, α-glucosidase, urease, and Factor Xa (FXa). Among the tested derivatives, K3, K5, K7, and K8 exhibited the most potent inhibitory activity, showing IC₅₀ values of 45.08 μM, 367.60 μM, 99.59 μM, and 21.69 μM toward FXa, α-amylase, urease, and α-glucosidase, respectively. Further analysis of the inhibitory effect of K8 against α-glucosidase revealed a mixed-type inhibition mechanism, indicating the ability of the compound to interact with both the free enzyme and the enzyme-substrate complex. Additionally, K3 was found to act as a reversible inhibitor of FXa, suggesting non-covalent interaction with the enzyme's active site and highlighting its potential as a selective anticoagulant candidate. Furthermore, ADME (absorption, distribution, metabolism, and excretion) analyses were performed to evaluate the drug-likeness and pharmacokinetic properties of the compounds, providing insights into their potential bioavailability and metabolic stability. In addition, molecular docking studies were conducted to rationalize the observed biological activities and to explore the binding modes of the ligands within the active sites of the target enzymes. The docking results demonstrated that key residues in the catalytic pockets contributed to hydrogen bonding, hydrophobic contacts, and van der Waals interactions, supporting the observed inhibitory profiles for the structure-activity relationships (SAR).