Antimicrobial Activity and Chemical Constituents of Essential Oil from the Leaves of Alpinia globosa and Alpinia tonkinensis

This paper reports the chemical constituents and the antimicrobial activity of essential oils hydrodisitlled from the leaves of Alpinia globosa Hour (syn. Amomum globosum Lour.) and Alpinia tonkinensis Gagnep. The essential oils were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS) techniques. The minimum inhibitory concentration (MIC) values were measured by the microdilution broth susceptibility assay. The absolute yields of the essential oils were 0.16 % (v/w, +/- 0.01) and 0.21 % (v/w, +/- 0.02), respectively for A. globosa and A. tonkinensis, calculated on a dry weight basis. The major constituents of A. biglobosa were beta-pinene (12.1 %), alpha-gurjunene (10.5 %) and (Z)-13-docosenamide (9.0 %). The compounds occurring in higher amount in A. tonkinensis includes beta-pinene (33.5 %), (E)-beta-ocimene (9.6 %), gamma-terpinene (9.2 %) and alpha-pinene (8.4 %). The essential oil of A. tonkinensis inhibited the growth of Saccharomyces cerevisiae (ATCC 16404) with MIC value of 25.0 mu g/mL. In addition, both essential oils displayed antimicrobial activity against Escherichia coli (ATCC 25922), Staphylococcus aureus subsp. aureus (ATCC 11632) and Fusarium oxysporum (ATCC 48112) with MIC value of 50.0 mu g/mL. The chemical constituents and antimicrobial activity of the studied essential oils were being reported for the first time.