Chemical and Enantioselective Characterization and Preliminary Biological Activities of Aristolochia lingulata...

Species of the genus Aristolochia are recognized as a rich source of structurally diverse specialized metabolites; however, the volatile chemical composition and biological properties of several Neotropical species remain poorly characterized. In particular, no information is currently available on the essential oil of Aristolochia lingulata Ule ex Pilg., which motivated this chemical, enantioselective, and preliminary biological investigation. The leaf essential oil was analyzed by GC-MS and GC-FID using nonpolar and polar stationary phases, while enantioselective GC-MS was employed to determine the distribution of selected chiral metabolites. Biological activity was evaluated through acetylcholinesterase, butyrylcholinesterase, pancreatic lipase, DPPH, and ABTS assays. A total of 57 constituents were identified and quantified, accounting for 93.5% and 91.3% of the oil on the two stationary phases. Sesquiterpene hydrocarbons and oxygenated sesquiterpenoids predominated, with dauca-5,8-diene, trans-(E)-nerolidol, β-chamigrene, β-cyclocitral, limonene, δ-amorphene, τ-muurolol, and manool among the main constituents. The oil showed moderate acetylcholinesterase inhibition (IC₅₀ = 79.8 ± 0.3 µg/mL), whereas weaker inhibition was observed against butyrylcholinesterase (IC₅₀ = 176.1 ± 3.3 µg/mL) and pancreatic lipase (IC₅₀ = 190.8 ± 9.4 µg/mL). Radical scavenging activity was also weak in the DPPH and ABTS assays (SC₅₀ = 849.7 ± 7.4 and 338.0 ± 3.9 µg/mL, respectively). Overall, this study provides the first characterization of the essential oil of A. lingulata, revealing a distinctive sesquiterpene-rich volatile profile and moderate enzyme-inhibitory activity. These findings expand the phytochemical knowledge of Neotropical Aristolochia species and provide a basis for further investigation of their bioactive constituents, mechanisms of action, and toxicological safety.