Flavones comprise one of the largest groups of flavonoids, which are characterized by the presence of a double bond between carbon-2 and carbon-3, and the attachment of the B ring to carbon-2. Various types of flavones have been reported in wood or bark of higher plants, including simple flavones, C-methyl flavones, 5,7,2',4'-tetrahydroxy derivatives, and 5,7,2',4',5'-pentahydroxy derivatives. Flavones play important roles in plant signaling, defense and human health due to their antioxidant, anti-inflammatory and other pharmacological activities.