Abstract

Four 9-epi-ent-labdanes were isolated from the aerial parts of Calceolaria inamoena. Their structures, 2?-hydroxy-9-epi-ent-labda8(17)-13(E)dien-15- oic acid, 2?-hydroxy-9-epi-ent-labda8(17)-13(Z)dien-15-oic acid, 2?-hydroxy-9-epi-ent-labda8(17)-13(E)dien-15-al and 2?-hydroxy-9-epi- ent-labda-8(17)-13(Z)dien-15-al, were established by spectroscopic methods including by analysis of 2 dimensional heteronuclear correlation experiments 1H/13C (normal and long range), and NOE and gs-sel-1D-NOESY and TOCSY of their methyl ester or acetyl derivatives. © 2004 Elsevier Ltd. All rights reserved.