Chemical compositions and antimicrobial activity of essential oil from the rhizomes of Curcuma singularis growing in Vietnam

Abstract

Curcuma singularis Gagnep., (Zingiberaceae) was found distributed in the Central Highlands of Vietnam and described as a new record for the country’s flora. From the fresh rhizomes of this plant, an essential oil was obtained by hydrodistillation with 0.31% yield (w/w). By GC-FID and GC-MS analysis, a total of 68 compounds were detected, of which 60 components accounting for 90.96% of the total oil were identified. Almost all of the components are mono- and sesquiterpenes (65 compounds, 98.57% total oil), most of them are oxygenated (51 compounds, 85.46% total oil). Major components are camphor (25.83%), germacrone (8.00%), caryophyllene oxide (4.48%), terpinen-4-ol (3.84%), and germacrone-4,5-epoxide (3.84%). In the antibacterial assays, the oil exhibited significant activity against the Gram positive bacteria Bacillus subtillis (MIC = 100 µg/ml) and the Gram negative bacteria Escherichia coli (MIC = 200 µg/ml).