The alkaloids (+)-crassif oline (6), (+)-claviculine (9) and (+)-norcularidine (12) have been obtained from Corydalis claviculata. (+)-Crassifoline possesses the S configuration st C-1. The phenolic groups in (+)-claviculine are at C-7 and C-3′. (+)-Norcularidine is a new natural product. © 1983 Japan Institute of Heterocyclic Chemistry. All rights reserved.