Chemical Composition and Selective Bioactivities of Piper platylobum Sodiro Essential Oil

Essential oils from the genus <i>Piper</i> are recognized for their chemical diversity and biological potential, yet <i>Piper platylobum</i> has been scarcely investigated. This study aimed to characterize the chemical composition of the leaf essential oil of <i>P. platylobum</i> 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-(<i>E</i>)-bergamotene (5.69%), (<i>E</i>)-caryophyllene (5.01%), and (<i>E</i>)-isocroweacin (3.75%). Biological assays revealed selective antimicrobial activity, with inhibition observed only against <i>Enterococcus faecium</i> (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 <i>P. platylabum</i> essential oil, highlighting its potential as a novel source of bioactive compounds.