Synthetic lanostane-type triterpenoids as inhibitors of DNA topoisomerase II.

DNA topoisomerase (Topo) II is one of the target enzymes for chemotherapeutic drug development. Lanostane-type triterpenoids with various functional groups (-Cl, -Br, -OMe, -CHO, -CN, -COOH, and -COOMe) at C-2 were synthesized from 3-oxolanost-9(11)-en-24S,25-diol (9) isolated from Pinus luchuensis and their inhibitory effects on Topo II activity and cytotoxic activities against A549 cells were examined. All the derivatives showed Topo II inhibitory effects with IC50 values ranging from 1.86 to 149.97 microM and cytotoxic activities with ED50 values ranging from 3.96 to 38.15 microM.