chemical composition and radical scavenging activity of essential oil and methanolic extract of eremostachys azerbaijanica rech.f. from iran

in the present study the volatile organic compounds of e. azerbaijanica rech.f. were identified. phytochemical assessment of meoh extract of aerial parts of this plant was also performed and its free radical scavenging properties was evaluated. the essential oil of the air-dried aerial parts was obtained by hydro-distillation using a clevenger type apparatus. the oil was then analyzed by gas chromatography–mass spectrometry and gas chromatography with flame ionization detector. soxhlet extraction was performed on the aerial parts using n-hexane, dichloromethane and meoh. the meoh extract was then subjected to solid-phase extraction using a c 18 sep-pak cartridge. isolation and structural elucidation of the pure components was done by high-performance liquid chromatography and spectroscopic methods (uv, 1 h-nmr). the free radical scavenging properties were determined by 2, 2-diphenyl-1-picrylhydrazyl (dpph) assay. a total of 59 components representing 95.9% of the oil constituents were identified which were primarily characterized by terpenoids or aliphatic skeletons. the major components of the oil were hexahydrofarnesyl acetone (27.1%), 2-methyl-6-propyl-dodecane (16.4%), and tricosane (9.3%). one flavonoid (luteolin-7-o-rutinoside) and one phenylethanoid (verbascoside) were isolated and identified from the meoh extract. the results of dpph showed that the essential oil of e. azerbaijanica possesses weak free radical scavenging properties. the meoh extract and its pure constituents showed significant activity (expressed as rc50) on dpph radicals.