Volatile profiling of Arnicão (Lychnophora salicifolia mart.), a wild medicinal species from Brazilian Cerrado

The Cerrado is a diverse Brazilian savanna with more than 12,000 species. Arnic~ao (Lychnophora salicifolia Mart – Compositae) is an endemic species occurring in central and southeast Brazil, at higher altitudes, in sandstone and quartzite soils. Lychnophora species have been reported for anti-inflammatory, antioxidant and UV protectant effects. Local communities use it to prepare traditional remedies (i.e. ointments or creams). The aim of this work was (1) to characterize the qualitative composition of L. salicifolia volatile fraction; (2) to evaluate the influence of the environmental conditions on the volatile fraction composition, by investigating plants harvested both in areas under stress conditions and protected from human interference; (3) optimizing a non-separative method for routine in-field analyses. Separative (HS-SPME-GC-MS) and non-separative (HS-SPME-MS) approach combined with PCA are proposed to discriminate between plant populations of L. salicifolia from two distinct areas. Forty-eight individuals were randomly collected from four populations. A clear separation between populations from protected and non-protected areas was observed, with an important presence of caryophyllene derivatives in populations from non-protected areas, usually with compounds associated to plant defense. Both analytical approaches gave the same results, confirming HS-SPME a useful approach for rapid in-field analysis of samples of wild populations.