Synthesis, evaluation of anti-breast cancer activity in vitro of ICS II derivatives and summary of the structure-activity relationship

A series of Icariside II (ICS II) derivatives were synthesized, and their structure-activity relationships (SARs) were studied in this paper. The in vitro antitumor activities towards human breast cancer cell lines (MCF-7) were evaluated by Cell Counting Kit-8 (CCK-8 kit). Preliminary results showed that, compared with ICS II, most of the derivatives displayed good micromole level activities. Among the series of derivatives, the S27, which totally acetylated hydroxyl of ICS II, possessed highest cytotoxicity, with IC50 values of 0.70 ± 0.08 μM. Furthermore, compound S27 showed better selectivity than ICS II for cancer cells over normal cells. Our findings indicate that compound S27 may be a promising anticancer lead candidate drug.