Phenolic compounds from aerial parts as chemosystematic markers in the Scorzonerinae (Asteraceae)

• 56 Phenolics were detected and characterized in 15 taxa from the genera Geropogon, Scorzonera, and Tragopogon.
• Seven caffeic acid derivatives and 15 flavonoids were identified.
• Multivariate data analysis of quantification results didn't yield characters to differentiate between the different genera.
• Closely related taxa of the Tragopogon pratensis s.l. group had similar profiles of phenolic compounds.
• On the other hand, Scorzonera hispanica s.l. taxa were more diverse with regards to their phenolic compound profiles.

In continuation of our chemosystematic survey of the Lactuceae tribe of the Asteraceae family and of the Scorzonerinae subtribe in particular, we have studied the profiles of phenolic compounds of aerial parts of Geropogon glaber L., and seven representatives of each of the genera Scorzonera and Tragopogon. Employing HPLC-MS3, 56 phenolics amongst the seven phenolic acids and 49 flavonoids were characterized. All phenolic acids were assigned as caffeoyl quinic acid derivatives and 15 of the flavonoids were identified as aglyca and glycoside of apigenin, luteolin, and quercetin, whilst the remaining flavonoids were only partially characterized. Multivariate data analyses of the HPLC-DAD quantification data revealed no significant differences between the three genera Geropogon, Scorzonera, and Tragopogon. However, some clusters of chemically very similar species amongst them the group of Tragopogon minor Mill., Tragopogon orientalis L., and Tragopogon pratensis L. (also regarded as subspecies of T. pratensis by some authors) were identified. In contrast, the three taxa of Scorzonera hispanica s.l. (Scorzonera crispatula Boiss., S. hispanica L., and Scorzonera trachysperma Guss.) were chemically less similar and partially clustered with other morphologically less closely related species.