A flavoprotein (FAD). The cofactor is covalently bound. Part of the cannabinoids biosynthetic pathway in the plant Cannabis sativa. The enzyme can also convert cannabinerolate (the (Z)-isomer of cannabigerolate) to Delta9-THCA with lower efficiency. Whereas the product was originally called Delta1-tetrahydrocannabinolate, the recommended name according to systematic peripheral numbering is Delta9-tetrahydrocannabinolate.