Grindelic acid is a labdane-type diterpene that was reported as the main secondary metabolite from Grindelia chiloensis Cabr and G. pulchella Dunal var. pulchella (Asteraceae). Recent studies demonstrated potential pharmaceutical applications for grindelic acid and its synthetic derivatives. Grindelic acid is a NOX4 inhibitor (IC50 2 uM). Grindelic acid’s mechanism of action is unknown, but it inhibited neither ROS in a cell-free membrane-based NOX4 assay nor from the purified NOX4 dehydrogenase domain. Grindelic acid demonstrates in vitro antitumor activity against human breast, cervix, lung,colon cancer.