Amentoflavone is a constituent of a number of plants with medicinal properties, including Ginkgo biloba and Hypericum perforatum (St. John’s Wort).

It is a biflavonoid (bis-apigenin

Apigenin

Apigenin is a flavone that is the aglycone of several glycosides. It is a yellow crystalline solid that has been used to dye wool. Apigenin may contribute to the chemopreventive action of vegetables and fruits...

 coupled at 8 and 3' positions).

Amentoflavone can interact with many other medications by being a potent inhibitor of CYP3A4

CYP3A4

Cytochrome P450 3A4 , a member of the cytochrome P450 mixed-function oxidase system, is one of the most important enzymes involved in the metabolism of xenobiotics in the body. CYP3A4 is involved in the oxidation of the largest range of substrates of all the CYPs. As a result, CYP3A4 is present in...

 and CYP2C9

CYP2C9

Cytochrome P450 2C9 is a protein that in humans is encoded by the CYP2C9 gene.- Function :CYP2C9 is an important cytochrome P450 enzyme with a major role in the oxidation of both xenobiotic and endogenous compounds. CYP2C9 makes up about 18% of the cytochrome P450 protein in liver microsomes...

, which are proteins used for drug metabolism in the body.