title: Variation of sesquiterpene lactone contents in different Arnica montana populations: influence of ecological parameters.
abstract: In ten grassland or heathland sites along a geographic (north to south) and climatic gradient in Germany, flowerheads of Arnica montana were collected, and the total content of sesquiterpene lactones (SLs) as well as the content of the detected single compounds were determined. The ratios of helenalin (H)- and corresponding 11 alpha,13-dihydrohelenalin(DH)-type compounds were calculated. All habitats were characterised concerning the climatic and soil conditions, and the values obtained were correlated with SL contents according to univariate statistical analyses. All populations showed very similar and constant ratios of helenalin ( 1)/11 alpha,13-dihydrohelenalin ( 2) at around 1.5-2/1 irrespective of different ecological parameters. The ratio of helenalin/11 alpha,13-dihydrohelenalin esters was several fold higher in all samples, but it was nearly identical in every habitat among each other, except for the helenalin/11 alpha,13-dihydrohelenalin 2-methylbutyrate pair ( 5/ 11), which showed a constantly twofold higher H/DH ratio. However, the 6- O-isovalerylhelenalin content ( 6) showed highly significant correlations to climatic factors.
authors.affiliation: Institute of Botany and Cell Biology, University of Regensburg, Regensburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Seemann
authors.forename: Teresa
authors.initials: T
authors.lastname: Wallner
authors.forename: Peter
authors.initials: P
authors.lastname: Poschlod
authors.forename: Jörg
authors.initials: J
authors.lastname: Heilmann
mesh_terms: D018650:Arnica / Q000737:chemistry* / Q000145:classification; D002980:Climate; D004463:Ecology; D007783:Lactones / Q000032:analysis*; D012717:Sesquiterpenes / Q000032:analysis*; D012987:Soil
chemical_list: D007783:Lactones; D012717:Sesquiterpenes; D012987:Soil