(-)-Viriditoxin is a mycotoxin originally isolated from A. viridinutans that has antibacterial and antiproliferative activity.{47137,47138,47139,47140} It is active against methicillin-sensitive and -resistant S. aureus (MSSA and MRSA, respectively), tetracycline-sensitive and -resistant Staphylococcus, vancomycin-sensitive and -resistant Enterococcus, and penicillin-sensitive and -resistant S. pneumoniae (MICs = 2-32 ?g/ml).{47138} (-)-Viriditoxin is also active against fish pathogens, including S. iniae and S. parauberis (MICs = 0.16-0.21 ?g/ml).{47139} It inhibits polymerization and the GTPase activity of E. coli FtsZ, a tubulin-like GTPase involved in bacterial cell division (IC50s = 8.2 and 7 ?g/ml, respectively).{47138} (-)-Viriditoxin inhibits proliferation of human DU145, LNCaP, and PC3 prostate cancer cells (IC50s = 5.36, 0.63, and 7.6 ?M, respectively) .{47140} It is also toxic to mice (LD50 = 2.8 mg/kg, i.p.).{47141}