Chemical compositions and antimicrobial activity of the essential oils of Hornstedtia havilandii (Zingiberaceae).

The chemical compositions and antimicrobial activity of the fresh rhizome and flower oils of Hornstedtia havilandii were studied. The components present were analyzed using GC and GC-MS. A total of forty-eight constituents were successfully identified from the flower and rhizome oils, representing 93.4% and 89.6%, respectively. The most abundant components of the flower oil were beta-pinene, (19.5%), beta-elemene, (10.0%), beta-cubebene, (6.2%), alpha-pinene, (5.6%), gamma-cadinene, (4.3%) and germacrene D, (3.3%), while alpha-copaene, (10.2%), beta-selinene, (8.4%), beta-elemene, (7.0%), gamma-cadinene, (6.9%), beta-cubebene, (5.3%) and germacrene D, (5.3%) were found as the main components of the rhizome oil. The essential oils were tested for antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria and yeasts. Both oils showed activity against the Gram-positive bacterium, Staphylococcus aureus, with moderate MIC values of 112.5 micro/mL, however, for Gram-negative bacteria, the flower oil showed weak antimicrobial activity with a MIC value of 225 microg/mL. Only very weak activity was shown against the yeasts Candida albicans and C. glabrata, with MIC values of 900-1800 microg/mL.