Quercetin

Quercetin is a bioflavonoid that occurs naturally in plants - this plant pigment is responsible for the colouration of flowers, while also offering protection against certain environmental influences. The blossoms of the Japanese pagoda tree (Sophora japonica) and the seeds of the Fava d'Anta tree are particularly rich in quercetin, and it can also be found in larger amounts in onions, apples and broccoli, although these are far more difficult to extract.