(5Z)-7-Oxozeaenol

(5Z)-7-Oxozeaenol is a natural resorcylic lactone derived from fungi that selectively inhibits purified TAK-1 (IC50 = 8.1 nM) without significantly affecting the kinase activities of other MAPKKK family members. 

In cells, (5Z)-7-Oxozeaenol is reported to irreversibly block IL-1-induced activation of TAK-1, NF-κB, and JNK/p38 with IC50 values of 65-83 nM.

(5Z)-7-Oxozeaenol has also been shown to inhibit IL-1-induced COX-2 production in cells and to relieve ear swelling induced by picryl chloride in a mouse model of COX-2-mediated inflammation.

Reference:

[1]. Ninomiya-Tsuji J, Kajino T, Ono K, et al. A resorcylic acid lactone, 5Z-7-oxozeaenol, prevents inflammation by inhibiting the catalytic activity of TAK1 MAPK kinase kinase. J. Biol. Chem, 2003, 278(20): 18485-18490.