title: [Helenalin- and 11,13-Dihydrohelenalinester from Flowers of Arnica montana.].
abstract: From the flowers of ARNICA MONTANA L. 13 helenanolides were isolated and identified. They are shown to be 11,13-dihydrohelenalin ( 1), helenalin ( 2) and their ester derivatives 3-13 (see figure). The natural occurence of 6-O-isobutyryl-, 6-O-tigloyl-, 6-O-isovaleryl- and 6-O-(2-methyl)-butyrylhelenalin (compounds 9, 11, 12, 13) is reported for the first time. The qualitative sesquiterpene lactone composition in flowers of A. MONTANA from different regions was found to be variable.
authors.affiliation: Institut für Pharmazeutische Biologie der Universität Düsseldorf.
authors.forename: G
authors.initials: G
authors.lastname: Willuhn
authors.forename: P M
authors.initials: PM
authors.lastname: Röttger
authors.forename: U
authors.initials: U
authors.lastname: Matthiesen