Isolated from the aflatoxin-producing mold Aspergillus parasiticus. The enzyme also catalyses the conversion of versiconal to versicolorin B (EC 4.2.1.143, versicolorin B synthase). Involved in aflatoxin biosynthesis.
Involvement of two cytosolic enzymes and a novel intermediate, 5'-oxoaverantin, in the pathway from 5'-hydroxyaverantin to averufin in aflatoxin biosynthesis.