The essential oil of Glossogyne tenuifolia

Glossogyne tenuifolia (Labill) Cass. (Compositae) is a traditional anti-pyretic and hepatoprotective herb in The Pescadores Islands. The essential oil of the dried herb, from four seasons, was isolated using a simultaneous steam-distillation and solvent-extraction (SDE) apparatus. The essential oil contents were in the range of 0.48–0.77 mg g−1, with an average of 0.66 mg g−1, and declined with the seasons. Generally, the essential oils from four seasons exhibited similar volatile profiles. A total of 62 different compounds were isolated by the SDE method and, among them, 30 compounds were identified, including 13 terpenes, 16 oxygen-containing compounds (eight alcohols, five aldehydes, one ester and two ketones) and one other compound. Terpenes were predominantly present in the essential oil and accounted for 61.3–76.0% of the essential oil with an average of 69.1%. The second most abundant class was alcohols, accounting for 12.4–15.9% of the essential oil, with an average of 14.1%. Consistently for four seasons, the most abundant eight compounds were in the descending order: p-cymene > β-pinene > β-phellandrene > limonene > cryptone > α-pinene > 4-terpineol + γ-muurolene. However, these eight compounds accounted for 71.5% of the average of the essential oil and, in combination, might give rise to the overall citrus-like aroma of the G. tenuifolia.