Abstract
In this study, antibacterial and anti-mildew fungal activities of the twig and fruit essential oil and its constituents from Eucalyptus citriodora were investigated in vitro against eight bacteria and seven mildew fungi, respectively. The major ingredient responsible for the antibacterial and anti-mildew fungal activities were also identified. The essential oil from the fresh twigs and fruits of E. citriodora were isolated using hydrodistillation in a Clevenger-type apparatus, and characterized by GC–FID and GC–MS, respectively. The twig oil consisted primarily of 1,8-cineole (17.7%), p-cymene (17.1%), caryophyllene oxide (13.8%), and isopulegol (12.2%); the fruit oil's main constituent was p-cymene (23.2%), α-pinene (16.1%), α-cadinol (11.5%), and τ-cadinol (8.4%). In addition, comparing the antibacterial and anti-mildew fungal activities of the oils showed that the fruit oil was the most effective. For the antibacterial and anti-mildew fungal activities of the fruit oil, the active source compounds were determined to be τ-cadinol and τ-cadinol.