Variation of sesquiterpene lactones in Lactuca aculeata natural populations from Israel, Jordan and Turkey

A comparative phytochemical study of seven sesquiterpene lactones in natural populations of the wild lettuce Lactuca aculeata Boiss (Asteraceae) was performed based on 23 accessions derived from eight two and single localities from Israel Jordan and Turkey respectively The compounds were profiled and quantified in leaves and roots of the plants grown from achenes (cypselas) in a greenhouse under controlled conditions using reverse phase HPLC with on-line photodiode array detector In the present study L aculeata was confirmed as a taxon strongly characterized by four dominant sesquiterpene lactones 8-deoxylactucin jacquinelin crepidiaside B and lactuside A An analysis of quantitative results of these four constituents led to the following conclusions (i) the sesquiterpene lactone contents varied significantly mainly within the populations however for two variables (crepidiaside B and lactuside A in root samples) the contents varied mostly between populations (ii) these differences are likely to be genetically controlled since all accessions were grown under standardized glasshouse conditions Accessions containing high levels of some sesquiterpene lactones were found in several populations These traits should be conserved in situ and ex situ and utilized in further research and lettuce improvement (C) 2010 Elsevier Ltd All rights reserved