Two members of a new class of C-nor-D-homo steroidal alkaloids, impranine (1) and dihydroimpranine (2) along with a new pyridyl-pregnane-type steroidal alkaloid, fetisinine (3) and a known base, korsevine (4) were isolated from the bulbs of Fritillaria imperialis. The structures of the compounds were established on the basis of spectroscopic techniques and some chemical transformations. Compounds I and 2 form a new class of steroidal alkaloids, named as impranane. (C) 2003 Elsevier Science Ltd. All rights reserved.