phenylpropanoid 1-benzopyran flavonoid 2-aryl-1-benzopyrans Flavonoid Any member of the 'superclass' flavonoids whose skeleton is based on 1-benzopyran with an aryl substituent at position 2. The term was originally restricted to natural products, but is now also used to describe semi-synthetic and fully synthetic compounds. flavonoids 2-aryl-1-benzopyran flavonoid oxoanion flavonoids