Thymol-Rich Lippia thymoides Mart. & Schauer (Verbenaceae) Essential Oil: Seasonal Chemical Variation, Antioxidant Capacity, Artemia salina Toxicity, and AChE Docking.

Essential oils are chemically complex natural products whose biological profiles may vary with volatile composition. This study integrated chemical characterization, antioxidant evaluation, Artemia salina lethality testing, and acetylcholinesterase (AChE) docking to investigate thymol-rich Lippia thymoides Mart. & Schauer (Verbenaceae) essential oil (LTEO) from leaves collected in September 2016 and February 2017. LTEO yield was higher in February 2017 (2.70%) than in September 2016 (2.24%). Overall, 38 constituents were identified, with thymol as the major compound in both samples (32.13% and 30.41%, respectively). The February sample showed higher proportions of monoterpene hydrocarbons, mainly p-cymene, γ-terpinene, and myrcene, whereas the September sample contained higher proportions of oxygenated monoterpenes, thymol acetate, and (E)-caryophyllene. Both samples showed radical-scavenging capacity, with numerically higher Trolox equivalent antioxidant capacity (TEAC) values for September. LTEO induced concentration-dependent lethality in A. salina, with LC50 values of 71.08 ± 7.06 µg mL- 1 for September and 60.06 ± 6.12 µg mL- 1 for February. Docking indicated that (E)-caryophyllene and thymol acetate had the most favorable dimensionless MolDock Scores. These findings reveal collection-period-related chemical differences and preliminary antioxidant, toxicological, and predictive AChE-interaction profiles. Interactions were dominated by hydrophobic and van der Waals contacts, supporting their interpretation as preliminary molecular evidence requiring future biochemical validation studies.