Requires iron(II) and ascorbate. The product spontaneously undergoes trans-cis isomerization followed by lactonization and cyclization, liberating CoA and forming umbelliferone. The enzymes from the plants Ruta graveolens and Ipomoea batatas also act on trans-feruloyl-CoA (cf. EC 18.104.22.168, feruloyl-CoA 6-hydroxylase).
Molecular cloning and functional analysis of the ortho-hydroxylases of p-coumaroyl coenzyme A/feruloyl coenzyme A involved in formation of umbelliferone and scopoletin in sweet potato, Ipomoea batatas (L.) Lam.