Annonaceae Essential Oils: Antimicrobial and Compositions of the Leaves of Uvaria hamiltonii Hook. f. & Thoms. and Fissistigma kwangsiensis Tsiang & P. T. Li

In this study, essential oils hydrodistilled from the leaves of Uvaria  hamiltonii Hook. f. & Thoms. and Fissistigma kwangsiensis  Tsiang & P. T. Li (Annonaceae) collected in Vietnam were analyzed by gas chromatographic techniques, and screened for the antimicrobial activities. The composition of both essential oils was dominated by sesquiterpenoids (70.0% and 78.7%, respectively). The main constituents of U. hamiltonii were germacrene D (22.9%), β-caryophyllene (21.1%), bicyclogermacrene (11.2%) and caryophyllene oxide (8.6%). The essential oil of F. kwangsiensis  also showed abundant sesquiterpenes β-caryophyllene (24.5%), d-cadinene (13.4%) and α-copaene (5.6%), but also included (Z)-β-ocimene (6.7%). The leaf oil of U. hamiltonii demonstrated notable antimicrobial activity against Enterococcus faecalis ATCC299212 with minimum inhibitory concentration (MIC) value of 7.99 µg/mL and Bacillus cereus ATCC14579 (MIC 5.67 µg/mL) while F. kwangsiensis  showed the most potent activity towards Pseudomonas aeruginosa ATCC27853 and Candida albicans ATCC10231, with MIC values of 3.45 µg/mL and 16.45 µg/mL, respectively. Both essential oils should be considered for further investigation as renewable “green” antimicrobial agents.