Daphnetin is a coumarin analog that acts as an inhibitor of several protein kinases. It inhibits EGFR kinase (IC50 = 7.67 ??M), PKA (IC50 = 9.33 ??M), and PKC (IC50 = 25 ??M), in vitro. The inhibition of EGFR kinase by daphnetin was competitive to ATP and non-competitive to the peptide substrate. Also acts as a potent antioxidant and anti-malarial agent.