Synthesis and cytotoxicity of longistylin C derivatives.

The present study was designed to identify potent anti-tumor compounds from a series of new longistylin C derivatives. Ten longistylin C derivatives were synthesized and their structures were confirmed by (1)H NMR, MS, and elemental analyses. Their cytotoxicity in vitro against three human cancer cell lines (A549, HepG2, and MCF-7) were evaluated by the MTT assay. Among these compounds, DT-6 and DT-9 displayed much better cytotoxicity against A549, HepG2, and MCF-7 cells, DT-1 exhibited selective cytotoxicity against HepG2, and the structure-activity relationships were investigated. In conclusion, Compounds DT-6 and DT-9 may serve as potential lead compounds for the discovery of new anti-cancer drugs.