Bis-cephalezomines A–E from Cephalotaxus harringtonia var. Nana

Five new dimeric Cephalotaxus alkaloids, bis-cephalezomines A–E (), have been isolated from the leaves of Cephalotaxus harringtonia var. nana, and the structures and stereochemistry were elucidated on the basis of spectroscopic data including 2D NMR and FABMS/MS spectra, and chemical means.