Inter-Individual versus Inter-Population Variability of Calendula suffruticosa subsp. algarbiensis Hexane Extracts.

Calendula suffruticosa subsp. algarbiensis (Boiss.) Nyman is very common on the Portuguese coast, but it has only recently begun to be studied chemically and belongs to a genus of difficult taxonomic classification. To improve the knowledge on the chemical variability of this taxon and evaluate the possible use of this tool for taxonomical purposes, the aim of this work was to determine the extent of chemical variation between individuals collected in the same geographic region, and to compare with samples mixing fragments of several individuals each (populations) from different local environments. Overall, hexane extract analysis by GC/MS allowed to identify 42 compounds, eight fatty acids, 24 terpenoids, three alcohols, five alkanes, and two pollutants. Greater chemical differences were found between individuals, grown in the same region, than were found between population samples from different regions. Additionally, 25 phytochemicals were identified for this taxon for the first time and may be used for taxonomic classification, even to distinguish between subspecies of C. suffruticosa. Furthermore, plants collected near urban areas accumulated pollutants, indicating the importance of controlling local environmental conditions when C. suffruticosa cultivation is for human consumption.