Analysis of Chemical Composition and Biological Activities of Essential Oils from Different Parts of Alpinia uraiensis Hayata

This study investigates the chemical composition and antioxidant and antifungal activities of essential oils (EOs) extracted from different parts of Alpinia uraiensis Hayata, an endemic species of Taiwan. EOs were obtained from flowers, leaves, stems, roots, and rhizomes using hydrodistillation, and their compositions were analyzed by gas chromatography–mass spectrometry (GC-MS). Monoterpene hydrocarbons and oxygenated monoterpenes were predominant, with flower and leaf EOs rich in γ-terpinene, terpinen-4-ol, and 1,8-cineole, while root EO was characterized by fenchyl acetate (72.2%). Antioxidant activity was evaluated using the DPPH assay, where the flower EO exhibited the highest radical scavenging activity (99.5% at 100 mg/mL), followed by rhizome and stem EOs, while root EO showed moderate activity. Antifungal activity against Phellinus noxius, a major wood-decaying pathogen, was assessed using the agar dilution method. Root EO exhibited the strongest antifungal effect, achieving complete inhibition at 400 and 800 μg/mL, while other EOs showed weaker activity. These findings suggest that A. uraiensis EOs possess potential antioxidant and antifungal properties, particularly the root EO, which may serve as a natural antifungal agent. Further studies are needed to elucidate the key bioactive compounds and their mechanisms for potential pharmaceutical and industrial applications.