β-caryophyllene as a chemical marker for the Lantana (Verbenaceae) genus
The Lantana genus consists of approximately 150 plant species, spanning from the tropics to the subtropics of the Americas, with a few members found in tropical Asia and Africa. A previous study of four genera from the Verbenaceae family (Lippia, Lantana, Aloysia and Phyla) proposed using iridoid glucosides as a taxonomic marker for this family. Unfortunately, the presence and type of iridoid glucosides in plants from the morphologically similar Lippia and Lantana genera are virtually indistinguishable, and so are not very helpful in differentiating between them. The current study aimed to provide further evidence to support the hypothesis of using the sesquiterpene β-caryophyllene as a unique chemical marker for plant species belonging to the Lantana genus. Two Brazilian Lantana species which had never been evaluated for their essential oil composition (L. lucida and L. salzmannii) were analyzed by GC and GC-MS. Results showed 17 predominant compounds for L. lucida, among which β-caryophyllene (19.0%) and α- caryophyllene (or humuleno, 33.0%) were the major components. L. salzmannii showed the presence of 58 compounds, the most abundant of which were β-caryophyllene (15.6%) and selin-11-en-4-ol (11.2%). In summary, the presence of β-caryophyllene in the two additional Lantana species evaluated here reinforced its use as a chemical marker for this genus.