The resultant half-maximal inhibitory concentration (IC50) values (Table and Figure ) enumerate the biological activities of those novel 3-substituted coumarins and validate our insilico prediction of their molecular pharmacology. The three compounds were discovered to exert potent inhibitory activities against the oncogenic carbonic anhydrase isoforms deployed in the study. On the downside, the compounds exhibited poor selectivity with nearly equivalent inhibition of carbonic anhydrases I and II, which indicates a risk of potentially unpleasant side effects. Nevertheless, the compounds still provide considerable insights into the design of powerful suicide inhibitors of carbonic anhydrases that may serve into shaping the future of this interesting class of therapeutic agents.