Honokiol (C18H18O2) is a biphenolic molecule present in the cones, bark, an leaves of Magnolia grandifloris that has been used in the traditional Japanese medicine Saiboku-to as an anxiolytic, anti-thrombotic, anti-depressant, anti-emetic, and anti-bacterial. While early research on the effective compounds in traditional remedies have simply used whole magnolia bark extracts, known as houpu magnolia, recent work has identified honokiol and its structural isomer magnolol as the active compounds in magnolia bark. In the late 1990's, honokiol saw a revival in western countries as a potent and highly tolerable anti-tumorigenic and neurotrophic compound.