Synthesis and cytotoxicity of the conjugates of diterpenoid isosteviol and N-acetyl-D-glucosamine

A series of conjugates of diterpenoid isosteviol (16-oxo-ent-beyeran-19-oic acid) and N-acetyl-D-glucosamine was synthesised and their cytotoxicity against several human cancer cell lines (M-Hela, MCF-7, Hep G2, Panc-1, PC-3), as well as normal human cell lines (WI-38, Chang liver) was assayed. Most of the conjugates were found to be cytotoxic against the mentioned cancer cell lines in the range of IC50 values 13–89 µM. Two lead compounds 14a and 14b showed selective cytotoxicity against M-Hela (IC50 13 and 14 µM) that was two times as high as the cytotoxicity of the anti-cancer drug Tamoxifen in control (IC50 28 µM). It was found that cytotoxic activity of the lead compounds against M-Hela cells is due to induction of apoptosis.