Prenylated flavonoids or prenylflavonoids are a sub-class of flavonoids. They are widely distributed throughout the plant kingdom. Some are known to have phytoestrogenic or antioxidant[1] properties. They are given in the list of adaptogens in herbalism. Chemically they have a prenyl group attached to their flavonoid backbone. It is usually assumed that the addition of hydrophobic prenyl groups facilitate attachment to cell membranes. Prenylation may increase the potential activity of its original flavonoid.[2]