A bacterial metabolite; has antifungal activity against S. pombe and R. javanicus (MICs = 0.05 and 2.13 μg/ml, respectively); halts the cell cycle at the G1 phase and induces nuclear condensation in L1210 cells at 5 ng/ml; inhibits nuclear-to-cytosolic transport of Rev in HeLa cells expressing Rev (IC50 = 6.3 nM); cytotoxic to L1210 and HCT-8 cells (IC50 = 1.8 and 1.6 ng/ml, respectively); reduces tumor growth in a variety of murine tumor and mouse xenograft models