Synthesis of (aminoalkyl)cycleanine analogues: cytotoxicity, cellular uptake, and apoptosis induction in ovarian cancer cells

Abstract Our previous studies demonstrated that cycleanine, a macrocyclic bisbenzylisoquinoline (BBIQ) alkaloid, showed potent anti-ovarian cancer activity via apoptosis induction. Here, we synthesized two novel (aminoalkyl)cycleanine analogues ( 2 and 3 ) through a simple and efficient two-step reaction starting from cycleanine isolated from Triclisia subcordata Oliv. These analogues showed greater potency than the unmodified cycleanine in three human ovarian cancer cell lines. Both 2 and 3 induced apoptosis in ovarian cancer cells by activations of caspases 3/7, cleavage of PARP, increase in subG 1 cell cycle phase and in the percentage of apoptotic cells. Further confocal fluorescence microscopy analysis confirmed the cellular uptake of alkaloids in ovarian cancer cells by using the unique (alkynyl)cycleanine ( 3 ) via click chemistry reaction. Our results suggest that cycleanine could be a hit compound for the future development in attacking ovarian cancer.