Chemical composition, antibacterial and antioxidant activity of the essential oils of <i>Metaplexis japonica</i> and their antibacterial components

Abstract

Abstract The aim of this research was to determine the chemical composition, antioxidant and antibacterial properties of the essential oils from Metaplexis japonica and isolation of antibacterial constituents from the essential oils. Results showed that 63 components were identified in essential oils. Phenylethyl alcohol (77.978%), α-terpineol (31.810%) and docosane (21.644%) were the most abundent constituents of flower oil, leaf oil and fruit oil, respectively. Based on bioactivity-guided fractionation, three active constituents were isolated and identified as phenylethyl alcohol, α-terpineol and β-linalool. Both flower oil and phenylethyl alcohol showed high antibacterial performance, with inhibition zone from 25 ± 0.5 to 11 ± 0.6 mm at highest concentration, and MIC values ranging from 0.125 to 2%. In both DPPH and ABTS assay, the oils showed moderate antioxidant activity. These results indicate potential efficacy of active constituents and essential oils of M. japonica to control food-borne pathogenic and spoilage bacteria.