Antimicrobial activity and chemical composition of essential oils of four Hypericum from Khorasan, Iran

Abstract

The essential oils obtained by hydrodistillation from the flowers, leaves, stems and roots or from four species Hypericum include Hypericum perforatum L., Hypericum hyssopifolium Vill.,Hypericum helianthemoides (Spach) Boiss. and Hypericum scabrum L. from plants growing wild in Khorasan, Northeast of Iran, were analyzed by gas chromatography (GC) and gas chromatography/mass spectral (GC/MS). In the oil of flowers, leaves, stems and roots fromH. perforatum, 47, 43, 30 and 34 (0.06 to 0.1%w/w); from H. hyssopifolium 42, 48, 45 and 44 (0.05 to 0.09%w/w); from H. helianthemoides 50, 49, 39 and 46 (0.05 to 0.09%w/w); and fromH. Scabrum 58, 43, 41 and 40 (0.04 to 0.1%w/w) components were identified, respectively. In the light conclusion and despite the morphological characters, H. perforatum L., H. hyssopifolium and H. scabrum could be placed in the pinene group, and H. helianthemoidesin the s-caryophyllene group. The in vitro antimicrobial activity of essential oils were also examined against seven microbial strains (gram positive and gram negative) by disc agar diffusion method and in general, the oils showed moderate activity against all tested microorganisms. Key words: Antimicrobial activity, Essential oils composition, Iran, Khorasan, HypericumSP, β-caryophyllene, α-pinene.