Abstract

The volatile constituents from the aerial parts of Pterocephalus canus growing wild in Iran was obtained by hydrodistillation and analyzed by GC and GC-MS. Twenty three components representing 95.3% of the oil were identified. The main constituents of the oil were naphthalene (42.4%), tridecanoic acid (7.9%), hexadecanoic acid (7.9%), tetradecamethylcycloheptasiloxane (3.4%), 2,3-butanediol (3.1%) and dodecanoic acid (2.1%). Antimicrobial activity of the oil against 6 Gram-positive and negative bacteria was determined by measuring the growth inhibition zone. The oil showed significant antimicrobial activity against Staphylococcus saprophyticus and Escherichia coli. The bacteriaStaphylococcus aureus, Sataphylococcus epidermidis, Salmonella typhi and Shigella flexnery were insensitive to the oil.

Key words: Pterocephalus canus, Dipsacacae, essential oil composition, antimicrobial activity.