Effect of Collection Time on Composition of Essential Oil of Lippia gracilis Schauer (Verbenaceae) Growing in Northeast Brazil

The specie Lippia gracilis Schauer is largely utilized for their antimicrobial properties, which are attributed to the presence of phenolic monoterpenes such as thymol and carvacrol. The aim of this study was to determine the yields and chemical composition of the essential oils obtained from fresh and dry leaves of collected at different times in the city of Crato-CE, in January 2009. The essential oils were extracted by hydrodistillation, and its components were identified by gas chromatography coupled with mass spectrophotometry. The time of plant collection should coincide with the moment of greatest expression of the active principle.