Investigating volatile compounds in the vapour phase of (1) a hot water infusion of rhizomes, and of (2) rhizomes of Siphonochilus aethiopicus using head space solid phase microextraction and gas chromatography with time of flight mass spectrometry

Abstract

Wild ginger, Siphonochilus aethiopicus, is a traditional remedy for the treatment of allergic asthma and other conditions. Preparations include hot infusions of rhizomes and steaming of the rhizomes and inhalation of the vapour. Volatile compounds in the vapour phase (representing the fraction that is inhaled) of both (1) a hot water infusion of fresh and air dried rhizomes and of (2) rhizomes were concentrated by head space solid phase microextraction (H/S-SPME) and analysed by gas chromatography with time of flight mass spectrometry (GC–TOFMS). Eucalyptol (1,8-cineole) was the major compound present in the vapour phase of a hot water infusion of fresh and dried rhizomes, and was also present as one of three major compounds in the vapour phase of fresh rhizomes. The drying of rhizomes caused a significant loss of eucalyptol and other compounds. Eucalyptol reportedly controls airway mucus hypersecretion and asthma. As such the presence of eucalyptol in the vapour phase of hot preparations may contribute to the anecdotal effectiveness of S. aethiopicus as a decongestant and traditional remedy for the treatment of allergic asthma.