Chemical variability of essential oils of Copaifera langsdorffii Desf. in different phenological phases on a savannah in the Northeast, Ceará, Brazil

Abstract

In most of the ethnobotanical studies among species with greater versatility, the Copaifera langsdorffii Desf. stands out due to the high number of therapeutic properties attributed to the oil-resin of its trunks. This species is widely distributed occurring both in preserved and anthropogenic environments. Plants that occur in different environmental conditions present qualitative and quantitative variation of the chemical constituents responsible for the biological activity, moreover, physiological factors can alter the synthesis of these compounds. This study aims to contribute with information about the chemical profile of C. langsdorffii in two areas of cerrado (preserved and anthropic) in different phenological phases and seasons. The vegetative (leaf fall and budding) and reproductive phenophases (flowering and fruiting) were qualified as present and absent from August 2013 to July 2014. In order to obtain the essential oils, the oil-resin were subjected to hydrodistillation process in an adapted Clevenger type device. The identification of the essential oils' chemical components was performed by gas chromatography coupled mass spectrometry (GC/MS). Statistical analyses of the results were obtained by Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA). The reproductive phase occurred only in anthropic areas. The essential oils of both areas had yields ranging from 5.1 to 28.8%; with higher yields at the end of the rainy season coincided with the fruiting phenophase in anthropic areas and the presence of only leaves in the conserved area. Total of 42 chemical constituents were identified, 27 common to the two areas. The main constituents were β-caryophyllene, α-humulene, germacrene B and caryophyllene oxide which presented changes in levels during all collections. Cluster analysis confirmed that the volatile oil of C. langsdorffii was strongly influenced in its chemical composition by the different areas (preserved and anthropic). These informations collaborate to establish the most appropriate collection period to obtain higher yields of Copaifera langsdorffii’s essential oil, as well as the desirable concentrations of the chemical compounds responsible for therapeutic activities.