Chemical constituents and antibacterial property of the essential oil of the roots of Cyathocline purpurea

Ethnopharmacological relevance: Cyathocline putpurea (D. Don.) O. Ktze. (Asteraceae) is a rare existence Indian medicinal plant and traditionally has antimicrobial property. Aim of the study: The aim of the present study was to identify chemical composition of the essential oil from the roots of Cyathocline purpurea and to screened in vitro antibacterial activity against eight human pathogenic bacteria. Materials and methods: The essential oil of roots was analyzed by using GC-FID and GC-MS. The antibacterial activity of oil was tested against four Gram-positive and four Gram-negative bacteria and antibacterial activity was determined by the tube dilution method. Results: The main constituents of the oil were thymohydroquinone dimethyl ether (57.4%) and beta-selinene (14.0%), among twenty five identified compounds, which represented 90.1% of the total oil. The oil was found active against Gram-positive bacteria with minimal bactericidal concentration (MBC) values in the range of 0.26-0.57 mg/mL. Conclusions: This is the first report on the chemical composition and antibacterial activity of the essential oil of roots of Cyathocline purpurea. The observation of MBC assay suggested that the Gram positive microorganisms were susceptible to essential oil, while oil was found to be resistant against Gram-negative bacteria, and the oil has bactericidal property. (C) 2012 Elsevier Ireland Ltd. All rights reserved.