Skepinone-L is an ATP-competitive, dibenzosuberone-based inhibitor of p38-MAPK and TNF-a, with IC50 values of 5 and 40 nM, respectively. [1] At 1000 nM, Skepinone-L (Kd = 1.5 nM) did not inhibit any other member of an Ambit panel of 402 kinases. [2]

In vitro HeLa cell assays determined that Skepinone-L showed a concentration-dependent inhibition of HSP27 (Ser82) phosphorylation at an IC50 of 25 nM. [2]. Furthermore, Skepinone-L reduced concentrations of well known p38 MAPK substrates, such as IL-1b and IL10 (IC50 = 30-50 nM). [2]