Homoerythrina-type alkaloids with neuroprotective activity from the branches of Cephalotaxus hainanensis Li

Lucidinine 13-N-oxide (1), one previously unreported homoerythrina N-oxide type alkaloid, and three known homoerythrina-type alkaloids (2-4) were isolated and elucidated from Cephalotaxus hainanensis Li. The structure of 1 were elucidated by extensive analysis of HRESIMS, 1D and 2D NMR data. The structures of three known alkaloids were elucidated by comparison with known compounds. The absolute configuration of 1 was estab-lished on the basis of experimental and computed ECD. All compounds was evaluated for neuroprotective ac-tivity against H2O2-induced apoptosis in human neuroblastoma SH-SY5Y cells. Lucidinine 13-N-oxide (1) significantly improved cell vitality of SH-SY5Y cells to 82.90 +/- 2.14% at concentration of 80 mu M.