The seeds of Lepidium sativum afforded five new dimeric imidazole alkaloids lepidine B, C, D, E and F in addition to the known imidazole alkaloid lepidine and two new monomeric imidazole alkaloids semilepidinoside A-and B. Their structure were elucidated on the basis of spectroscopic evidence. (C) 1998 Elsevier Science Ltd. All rights reserved.