Investigation of podophyllotoxin esters as potential anticancer agents: synthesis, biological studies and tubulin inhibition properties.

A series of fifteen podophyllotoxin derived esters have been synthesized and their anti-cancer properties have been evaluated against A549 (lung cancer), DU-145 (prostate cancer), HepG2 (liver cancer), HeLa (cervical cancer) and MCF-7 (breast cancer) cell lines. Five compounds of the series 8a, 8g-h, 8m and 8o showed IC50 values in the range of 0.71-10.94 μM. Among compounds, 8g and 8h showed significant cytotoxicity towards all the types of cancer studied. Cell cycle analysis revealed that the compounds 8a, 8m and 8o inhibit proliferation by cell cycle arrest. Also Hoechst-positive nucleus indicating apoptosis of these cells was observed in presence of 8g-h. Further studies revealed that these compounds inhibit tubulin polymerization and leads to the inactivation of AKT/PKB that are known to play an important role in the proliferation of cancer cells.