A coumarin derivative with diverse biological activities; inhibits EGFR, PKA, and PKC in vitro (IC50s = 7.67, 9.33, and 25.01 μM, respectively); inhibits cell proliferation (IC50 = 73 μM) in MCF-7 breast carcinoma cells; decreases the generation of ROS and production of MDA and increases SOD activity and the GSH:GSSG ratio in RAW 264.7 cells; prevents t-BHP-induced cytotoxicity and ROS overproduction in wild-type, but not Nrf2-/-, RAW 264.7 cells and increases the expression of proteins downstream of Nrf2