Varronia curassavica Jacq. (Boraginaceae) is a native species of the Atlantic Forest with medical importance. This study determined the essential oil variation of 16 populations of V. curassavica of restinga in Santa Catarina, Brazil, in response to drying and edaphoclimatic conditions. The populations supplied essential oil with a content between 0.27 to 1.15% in the summer and from 0.33 to 1.12% in the winter. 41 chemical compounds were identified in the summer and 40 in the winter. The compounds were grouped into 4 chemical classes in each station studied. The common chemical constituents found in the essential oil of all populations and in both seasons were α-thujene, α-pinene, sabinene, α-humulene, (E)-cariophylene, spatulenol, mircene, allo-aromadendrene, β-sesquifelandreno and α-zingiberene. Cluster analysis using the nearest neighbor method based on Euclidean distance grouped the 16 populations into 3 groups in the summer and 8 groups in the winter. As the habitats have distinct pedological characteristics, we identified that pH, organic matter, sum of bases and base saturation are associated with the synthesis of (E)-caryophyllene, α-humulene, and allo-aromadendrene from populations.

The restinga is an Atlantic Forest ecosystem characterized by tree, shrub, and herb species that are rich sources of essential oils. In this study, we aim to quantify the essential oil content and determine the chemical constituents of fresh leaves of 14 plant species in a restinga stretch in southern Brazil. Essential oils were obtained by hydrodistillation in a Clevenger-type apparatus and analyzed by gas chromatography coupled to mass spectrometry. Campomanesia reitziana, Cortaderia selloana, and Sophora tomentosa had no essential oils. Total essential oil content ranged from 0.01% (Mikania involucrata) to 1.56% (Varronia curassavica). In total, 60 chemical constituents were identified, representing between 46.2% and 96.5% of the chemical composition of the essential oils. Limonene was the common constituent in all species in which the essential oils were present. The major constituents were ar-curcumene (15.1%) and cis-chrysanthenol (14.2%) in Ambrosia elatior; benzyl benzoate (43.5%) and benzyl salicylate (23.7%) in Aniba firmula; caryophyllene oxide (35.7%) and spathulenol (10.6%) in Austroeupatorium inulaefolium; spathulenol (19.8%) and caryophyllene oxide (14.0%) in Baccharis spicata; caryophyllene oxide (16.3%) in Eugenia astringens; curzerene (30.0%), limonene (13.0%), and germacrone (11.9%) in Eugenia uniflora; caryophyllene oxide (17.1%) and ledol (11.3%) in Lantana camara; caryophyllene oxide (27.7%) and limonene (12.7%) in M. involucrata; 1,8-cineole (19.8%) in Psidium cattleianum; limonene (10.2%) in Schinus terebinthifolius, and allo-aromadendrene (15.2%) in V. curassavica. We expect that our results can assist in selecting species of potential interest for herbal, phytotherapeutic, and cosmetic products.