Cephalotaxine-type and homoerythrina-type alkaloids with antiproliferative effects from Cephalotaxus fortunei

Twenty-two cephalotaxine-type and ten homoerythrina-type alkaloids, including seven previously undescribed ones, were isolated from the twigs and leaves and the seed kernels of Cephalotaxus fortunei . Their structures were established by spectroscopic analysis, single crystal X-ray diffraction, and ECD calculation methods. Cephalofortunine A β- N -oxide (1) is the first nitrogen-oxidized homoerythrina-type alkaloid. The isolated compounds were evaluated for their in vitro antiproliferative effects against two human leukemia cell lines (THP-1 and K562). All compounds showed different levels of antiproliferation in THP-1 and K562 cells with GI 50 values of 0.24–29.55 μM. Hainanensine (31) was the most active against two cancer cell lines with GI 50 values of 0.24 ± 0.07, and 0.29 ± 0.01 μM, respectively.