Antroquinonol is an enone with a cyclohex-2-en-1-one core substituted by a hydroxy group at position 4, methoxy groups at positions 2 and 3, a methyl group at position 6, and a (2E,6E)-3,7,11-trimethyldodeca-2,6,10-trien-1-yl group at position 5 (the 4R,5R,6R stereoisomer). Isolated from the solid-state fermented mycelium of *Antrodia camphorata*, it exhibits potent cytotoxicity against various human cancer cell lines. However, a 2016 synthesis-enabled re-examination showed minimal in vitro and in vivo antitumour activity in preclinical models. It functions as an antineoplastic agent and a fungal metabolite, and is classified as an enone, secondary alcohol, and enol ether.
