Amentoflavone

Amentoflavone is a biflavonoid ("bis"-apigenin coupled at 8 and 3' positions, or 3′,8′′-biapigenin) constituent of a number of plants including "Ginkgo biloba", "Chamaecyparis obtusa" (hinoki), "Hypericum perforatum" (St. John's Wort) and "Xerophyta plicata".
Amentoflavone can interact with many medications by being a potent inhibitor of CYP3A4 and CYP2C9, which are enzymes responsible for the metabolism of some drugs in the body. It is also an inhibitor of human cathepsin B.
Amentoflavone has a variety of "in vitro" activities including antimalarial activity, anticancer activity (which may, at least in part, be mediated by its inhibition of fatty acid synthase), and antagonist activity at the κ-opioid receptor ("K"e = 490 nmol L−1) as well as activity at the allosteric benzodiazepine site of the GABAA receptor as a negative allosteric modulator.