(5E)-7-Oxozeaenol ("iso-LL Z1640-2") is a resorcylic acid lactone belonging to the zearalenone class, recognised as a minor metabolite of the fungus, Drechslera portulacae. (5E)-7-Oxozeaenol was rediscovered as a major analogue of a resorcylic acid lactone complex from a Phoma-related species by Pierce and colleagues in 2011. (5E)-7-Oxozeaenol is the double bond isomer of LL Z1640-2 ((5Z)-7-oxozeaenol), a selective TAK 1 inhibitor. (5E)-7-Oxozeaenol exhibits moderate anti-tumor activity and NF-KB inhibitory activity but is otherwise unexplored.