Burkholone, a new cytotoxic antibiotic against IGF-I dependent cells from Burkholderia sp.

Abstract

In the course of our screening program for new inhibitors of IGF-I signaling, we isolated a new cytotoxic antibiotic, burkholone, from the culture broth of Burkholderia sp. QN15488. The structure of burkholone was determined to be (E)-3-methyl-2-(2-octenyl)-4-quinolone by a series of NMR analyses. Burkholone induced cell death 32D/GR15 cells with an IC50 value of 160 nM in IGF-I containing medium, while no cell death was observed in IL-3 containing medium even at the concentration of 37 μM. © Japan Antibiotics Research Association.