Antibiotic that inhibits bacterial protein synthesis. Inhibits mRNA-tRNA translocation by GTPase elongation factor G (EF-G), EF-TU(GTP)-catalyzed aa-tRNA delivery and the activity of initiation factor 2 (IF-2). Antitumor agent; induces cell cycle arrest and apoptosis in breast cancer cells via downregulation of FOXM1 expression.