Ammocidin, a new apoptosis inducer in Ras-dependent cells from Saccharothrix sp. I. Production, isolation and biological activity.

A new apoptosis inducer, ammocidin, was isolated from the culture broth of Saccharothrix sp. AJ9571. Ammocidin induced apoptotic cell death in Ras-dependent Ba/F3-V12 cells with an IC50 of 66 ng/ml. No cell death was observed in IL-3-dependent Ba/F3-V12 cells at less than 100 microg/ml of ammocidin. Ammocidin significantly reduced the phosphorylation level of MAPK and S6K that mediate the anti-apoptotic function of Ras.