Coumarins as a base for the drug development: yes or no?

It is well known that coumarin derivatives are widely distributed in nature and have a wide spectrum of biological activity. At the same time, only a few compounds containing a coumarin fragment are used in the clinics. These compounds include for example the anticoagulant warfarin and the anthelmintic drug haloxon. In the present article is discussed the few examples of biological activity of coumarin derivatives, the mechanisms of action of these compounds and the problems that arise in the development of new drugs, as well as the prospects for using coumarins as leader compounds.