Homogeranyl nerol derivatives and a melampolide from Smallanthus glabratus

The investigation of the aerial parts of Smallanthus glabratus from two locations afforded the same known compounds but some additional new compounds which were not present in both collections. From the first location typical melampolides, one of them not isolated previously, and two homoditerpenes were isolated. The material from the second location gave four closely related homoditerpenes and two geranyl nerol derivatives from which the homoditerpenes were derived. The structures were elucidated by high field ¹H NMR spectroscopy. Chemotaxonomic aspects are discussed briefly.