A natural quinoid diterpene that, at 10-20 µM, stimulates AMPK in C2C12 myotubes and activates p38 MAPK in DU145 cells; inhibits SHP2 in vitro (IC50 = 22.5 µM) and, at 4-8 µM, blocks phosphorylation of STAT3 in MC-3 cells; has a variety of anti-cancer actions.