Abstract
The genus Cistus is taxonomically complex, as taxonomic classification of individual species based
on morphological criteria is often difficult and ambiguous. However, specific species
contain valuable natural products, especially terpenoids and polyphenols, which exert
various biological effects and might therefore be used for treatment of a broad array
of disorders. Hence, a fast and reliable method for clear identification of different
Cistus (sub-) species is required. Approaches for analysis of secondary metabolite profiles,
e.g., with NMR, might remedy the challenging classification of Cistus (sub-) species and help to identify specific markers for differentiation between
them. In the present study, 678 samples from wild-growing Cistus populations, including 7 species and 6 subspecies/varieties thereof, were collected
in 3 years from populations in 11 countries all over the Mediterranean basin. Samples
were extracted with buffered
aqueous methanol and analysed with NMR. From the resulting 1D-1H-NOESY and J-Res profile spectra, marker signals or spectral regions for the individual
(sub-) species were identified with multivariate statistical tools. By examining the
NMR profiles of these extracts, we were able to identify discriminators and specific
markers for the investigated Cistus (sub-) species. Various influencing factors, like (sub-) species, wild harvestings
of different populations from several countries, numerous collection sites, different
years, and cultivation in greenhouses have been considered in this work. As the here
identified markers are independent from these influencing factors, the results can
be considered a robust model and might be used for future differentiation between
Cistus (sub-) species.
Key words
Cistus L. - Cistaceae - NMR-secondary metabolites - metabolic fingerprinting - chemotaxonomic
classification
