(-)-Chaetominine

(-)-Chaetominine is a cytotoxic alkaloid originally isolated from Chaetomium sp. IFB-E015.{43151} It inhibits the growth of K562 leukemia and SW1116 colon cancer cells (IC50s = 20 and 28 nM, respectively). (-)-Chaetominine induces apoptosis of K562 cells via upregulation of the Bax/Bcl-2 ratio, decreasing mitochondrial membrane potential, inducing mitochondrial cytochrome C release, and activation of caspase-3 and caspase-9.{43152} It also decreases doxorubicin efflux mediated by multidrug resistance-associated protein 1 (MRP1) and restores sensitivity to doxorubicin (Item No. 15007) in resistant K562 cells.{43153}