Synthesis, characterization and in vitro antiproliferative effects of isosteviol derivatives.

Nineteen isosteviol derivatives were designed and synthesized by C-16, C-19 and D-ring modifications of isosteviol. These compounds were screened for their cytotoxic activities against Hela and A549 cells in vitro . Among them, the inhibitory effect of compounds 3b and 16 on Hela cells was comparable to that of the positive control gefitinib, and the compounds 3b (IC 50 =7.84 ± 0.84 μM) and 7a (IC 50 =6.89 ± 0.33 μM) exhibited significant cytotoxicity superior to gefitinib (IC 50 =11.02 ± 3.27 μM) against A549 cells.