Essential oil composition and antimicrobial activity of Artemisia dracunculus L. var. qinghaiensis Y. R. Ling (Asteraceae) from Qinghai-Tibet Plateau

Many plant species that occur at the high-altitudes such as Qinghai-Tibet Plateau (QTP) under extreme climate conditions have potential medicinal functions. To explore the potential use of such plants, we extracted the essential oil from Artemisia dracunculus var. qinghaiensis Y. R. Ling collected from QTP at the flower-buds stage (0.67% v/w) by the hydro-distillation method. The chemical compositions and antimicrobial activity of the essential oil were determined using the gas chromatography/mass spectrometry (GC/MS) and agar disk-diffusion methods, respectively. Thirty-seven compounds accounting for 60.88% of the total detected components, with a high proportion of monoterpenes (42.12%) were identified in the essential oil. Of these, sabinene (19.19%), beta-terpinene (8.94%), terpinen-4-ol (3.83%), and alpha-pinene (3.08%) were identified as the major compounds. The essential oil showed inhibitory activity against seven microbial strains (Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella paratyphi, and Saccharomyces cerevisiae) at the minimum concentrations (MICs) of 1.25-5.0 mu l/ml. Our results suggest that the essential oil of the QTP A. dracunculus var. qinghaiensis can be used as a potential biomedical resource.