Chemical Composition of the Essential Oils of Pogostemon auricularius, a Vietnamese Medicinal Plant

The essential oils from the stems, the leaves, and the flowers of Pogostemon auricularius, growing wild in Vietnam, were obtained by hydrodistillation and analyzed by gas chromatography – mass spectrometry. The essential oils were dominated by sesquiterpenoids (62.3–71.0%) and diterpenoids (23.9–27.3%), with β-caryophyllene (20.7–31.5%), α-humulene (8.9–14.1%), and ( E,E)-geranyl linalool (14.0–19.6%) as major components. The abundant concentrations of β-caryophyllene and α-humulene, known analgesic and anti-inflammatory agents, likely account for the traditional use of P. auricularius in Vietnam to treat fevers, malaria, and sore throat.