Design, semi-synthesis and bioevaluation of koumine-like derivatives as potential antitumor agents in vitro and in vivo

Aims: Five series of novel koumine-like compounds were designed, semi-synthesized and systematically evaluated for antitumor activities. Methods: All compounds were evaluated for antiproliferative activity against four human cancer cell lines, including HT-29, HCT-116, HCT-15 and Caco-2. Results: Most compounds exhibited much higher antiproliferation activities (IC50 <10 μM) than koumine. Two selected compounds A4 and C5 showed comparable antitumor effects to 5-FU in vivo, as well as better safety profiles. Further studies suggested that A4 and C5 could arrest HT-29 cell cycle in G2 phase and raise reactive oxygen species level, thus inducing cell apoptosis related to Erk MAPK and NF-κB signaling pathways inhibition. Conclusion: These results will greatly promote the druggability study of these koumine-like compounds.