Chemical Composition and Selective Bioactivities of Piper platylobum Sodiro Essential Oil

Essential oils from the genus Piper are recognized for their chemical diversity and biological potential, yet Piper platylobum has been scarcely investigated. This study aimed to characterize the chemical composition of the leaf essential oil of P. platylobum and evaluate its antimicrobial, antioxidant, and anticholinesterase activities. The oil was obtained by steam distillation and analyzed through gas chromatography–mass spectrometry (GC-MS) and gas chromatography equipped with a flame ionization detector (GC-FID), leading to the identification of 35 compounds that accounted for 91.11% of the volatile fraction. Dillapiole (42.0%) was the principal constituent, followed by α-(E)-bergamotene (5.69%), (E)-caryophyllene (5.01%), and (E)-isocroweacin (3.75%). Biological assays revealed selective antimicrobial activity, with inhibition observed only against Enterococcus faecium (MIC = 1000 µg/mL), while no effect was detected against other bacterial or fungal strains tested. Antioxidant evaluation showed moderate activity in the ABTS assay (SC₅₀ = 335.71 ± 1.43 µg/mL; TEAC = 45.85 ± 1.68 µM Trolox/g EO), but no activity in the DPPH assay. The essential oil also displayed moderate inhibition of acetylcholinesterase (IC₅₀ = 76.86 ± 1.00 µg/mL), suggesting a potential role in neuroprotective applications. This study constitutes the first report on the chemical composition and biological activities of P. platylabum essential oil, highlighting its potential as a novel source of bioactive compounds.