Fistulopsines A and B antiproliferative septicine-type alkaloids from Ficus fistulosa

Abstract Two new septicine-type alkaloids, fistulopsines A and B ( 1 and 2 ), together with four known phenanthroindolizidine alkaloids ((+)-septicine, (+)-tylophorine, (+)-tylocrebrine, and (–)-3,6-didemethylisotylocrebrine) and (+)-(6 S ,9 S )-vomifoliol, were isolated from the bark and leaves of Ficus fistulosa . The structures of these compounds were established by spectroscopic analysis. Fistulopsines A and B ( 1 and 2 ) showed in vitro growth inhibitory activities in HCT 116 and MCF7 cell lines with GI 50 ranging between 2–7 μM. Furthermore, both compounds 1 and 2 were found to predominantly arrest cells in G1 phase of the cell cycle without induction of apoptosis. HCT 116 cell cycle perturbation by both compounds was found to be transient (