Simocyclinone D8: Exploring a new mechanism of topoisomerase II inhibition

AEI 88

Keith C. Ellis, ellis334@umn.edu, Department of Medicinal Chemistry and the Institute for Therapeutic Discovery and Development, University of Minnesota, 717 Delaware St SE, Minneapolis, MN 55414
Topoisomerase II is a validated anti-cancer target for the treatment of thirteen cancers including small cell lung cancer and many lymphomas. Current topoisomerase II inhibitors act by stabilizing the DNA-topoisomerase II complex, interrupting DNA synthesis and inducing cell death. Simocyclinone D8 is a natural product that has been shown to inhibit topoisomerase II by a new mechanism of action. It is as potent as the front line therapies etoposide and doxorubicin, to which many tumors are becoming resistant. In order to determine the molecular basis for this novel mechanism of action, we are exploring the medicinal chemistry of simocyclinone D8. The natural product has been produced by fermentation from the bacteria S. antibioticus Tu6040, isolated, and purified. Preliminary studies into the absolute structure of simocyclinone D8 and the preparation of derivatives by semi- and total synthesis to probe the structure-activity relationship of this new topoisomerase inhibitor will be reported.