Introduction . The Fe II /α-ketoglutarate-dependent fungal dioxygenase AsqJ from Aspergillus nidulans was discovered in 2014 by Watanabe et al.1and characterised as a key enzyme in the biosynthesis of fungal alkaloids, such as the aspoquinolones A and B ( 1 and 2 , Fig.? 1a )2 , 3 , 4. The non-heme enzyme catalyses a fascinating reaction cascade, involving a one-pot desaturation/epoxidation reaction of a N 4-methylated benzo[1,4]diazepine-2,5-dione 3 wi...