Seasonal Effect on the Chemical Composition of Lippia alba Volatile Chemotypes.

Lippia alba (Verbenaceae) is a native Brazilian medicinal species with varied applications, notable for the diversity of volatile chemotypes defined by the major compounds of its essential oil, with fewer studies of its nonvolatile composition. The objective of this work was to perform the chemical characterization via GC-MS and LC-MS of five L. alba individuals, collected during the rainy and dry season. The chromatographic results were analyzed via untargeted metabolomics. Four of the five individuals maintained the same major essential oil composition between the two periods evaluated and each volatile chemotype presented distinct major compounds. The nonvolatile composition, however, was similar for the five L. alba individuals. Some volatile and nonvolatile compounds varied between seasons, demonstrating a discrete effect of the environment on their chemical composition. These results are fundamental for the medicinal application and quality control of this species.