Spatial and Temporal Variations in Secondary Metabolites Content of the Brazilian Arnica Leaves (Lychnophora ericoides Mart., Asteraceae)

The genus Lychnophora (Asteraceae) is a medicinal plant traditionally used as anti-inflammatory or analgesic agent. Its biological properties have been widely investigated and correlated with its chemical composition, which could be different between the species and even accordingly to the place and season of collection. In this work, it was investigated the spatial and temporal variations in the secondary metabolites from five populations of Lychnophora ericoides. Among them, a more diversified secondary metabolism was observed for the plants collected at Ibiraci-MG (Brazil), a city placed between two biomes, Cerrado and Atlantic Forest. The highest concentrations of chlorogenic acids were found in the Cerrado dry season (winter), while the flavonoids were higher during the rainy season (summer). Significant reduction was observed in the contents of all the secondary metabolites in old leaves, and also in flowery branches. These variations detected in L. ericoides leaves could highly influence the intensity of the biological activities of this plant.