Thrombosis is the leading cause of illness and mortality worldwide, posing a serious risk to human health and life. Because antithrombotic drugs can prevent the beginning and progression of thrombotic disorders, they are essential in the management of thrombotic diseases. The substantial side effects and unsatisfactory efficacy of present antithrombotic drugs stimulate the search for novel, effective, and safer antithrombotic therapies. Natural and synthetic coumarins have been shown to have antithrombotic action, specifically anticoagulation, and antiplatelet aggregation. In particular, coumarin-based medications like warfarin, phenprocoumon, and cloricromen have long been used to treat thrombosis in clinical settings. The favored structure for creating novel antithrombotic medications with diverse modes of action is coumarin, which has low toxicity. The goal of the current review is to consolidate recent findings on the development of coumarins as antithrombotic agents, with a focus on the connection between these compounds’ chemical compositions and therapeutic potency. It aims to offer promising suggestions for the identification of new coumarin compounds with potent antithrombotic properties.

The first outbreak in Wuhan, China, in December 2019 was reported about severe acute coronaviral syndrome 2 (SARS-CoV-2). The global coronavirus disease 2019 (COVID-19) pandemic in 2020 resulted in an extremely high potential for dissemination. No drugs are validated in large-scale studies for significant effectiveness in the clinical treatment of COVID-19 patients, despite the worsening trends of COVID-19. This study aims to design a simple and efficient cyclo-condensation reaction of 6-aminouracil derivatives 2a–e and isatin derivatives 1a–c to synthesize spiro-oxindoles 3a–d, 4a–e, and 5a–e. All compounds were tested in vitro against the SARS-CoV-2. Four spiro[indoline-3,5′-pyrido[2,3-d:6,5-d’]dipyrimidine derivatives 3a, 4b, 4d, and 4e showed high activities against the SARS-CoV-2 in plaque reduction assay and were subjected to further RNA-dependent-RNA-polymerase (RdRp) and spike glycoprotein inhibition assay investigations. The four compounds exhibited potent inhibitory activity ranging from 40.23 ± 0.09 to 44.90 ± 0.08 nM and 40.27 ± 0.17 to 44.83 ± 0.16 nM, respectively, when compared with chloroquine as a reference standard, which showed 45 ± 0.02 and 45 ± 0.06 nM against RdRp and spike glycoprotein, respectively. The computational study involving the docking studies of the binding mode inside two proteins ((RdRp) (PDB: 6m71), and (SGp) (PDB: 6VXX)) and geometrical optimization used to generate some molecular parameters were performed for the most active hybrids.