MINOR COMPONENTS WITH SMOOTH-MUSCLE RELAXING PROPERTIES FROM SCENTED MYRRH (COMMIPHORA-GUIDOTTI)

All sesquiterpenes present in a sample of scented myrrh were isolated and characterised. Seven compounds, with cadinane, guaiane, oplopane, and eudesmane skeletons, were obtained, of which two are new and two a re reported from a natural source for the first time. The major compon ent, T-cadinol, has previously been shown to possess smooth muscle-rel axing properties, and the major purpose of the investigation was to co mpare the effects of the minor and more polar sesquiterpenes with that of T-cadinol in the rat aorta. Like T-cadinol, the minor sesquiterpen es are more efficient in reducing K+-induced contractions than those i nduced by the alpha-adrenoceptor agonist phenylephrine, however, they were all less potent than T-cadinol.