Centaureidin, a cytotoxic flavone from Polymnia fruticosa, inhibits tubulin polymerization. John A. Beutler, John H. Cardellina, Chii M. Lin, Ernest Hamel, Gordon M. Cragg and Michael R. Boyd, Bioorganic & Medicinal Chemistry Letters, Volume 3, Issue 4, April 1993, pages 581-584, doi10.1016/S0960-894X(01)81233-6