Rearranged and enantiomeric alkaloids from Cephalotaxus sinensis

• Three new alkaloids were isolated from Cephalotaxus sinensis . • Cephalosinine A ( 1 ) is a novel rearranged Cephalotaxus alkaloid, featuring an uncommon 6/6/6/5 ring system. • Homoerythrina-type alkaloids were evaluated for their in vitro hearing protective effects. Three undescribed alkaloids ( 1 – 3 ) along with 30 known ones were isolated from the twigs and leaves of Cephalotaxus sinensis . The structures of the new alkaloids were determined through comprehensive spectroscopic analysis and ECD calculations. Cephalosinine A ( 1 ) with 6/6/6/5 ring system represents a new type of Cephalotaxus alkaloid, which might be formed through a rearrangement from simultaneously isolated cephalotaxinone. Cephalolancine B ( 2 ) was the second cephalolancine skeleton alkaloid. (+)-Acetylcephalotaxine β - N -oxide ( 3 ) was an enantiomeric Cephalotaxus alkaloid. The isolated homoerythrina-type alkaloids were evaluated for their in vitro hearing protective effects against neomycin-induced cell death in HEI-OC-1 cells.