| In the present study, the chemical composition of the essential oil and methanol (MeOH) extract of
aerials of E. azerbaijanica were identified. Furthermore, the free radical scavenging properties of
the volatile oil as well as the MeOH extract of the plant were assessed. 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
Sep-Pak cartridge. Isolation and
structural elucidation of the pure components was accomplished by high-performance liquid chromatography
and spectroscopic methods (UV,
1
18
H-NMR). The free radical scavenging properties were determined by 2, 2diphenyl-1-picrylhydrazyl
(DPPH)
assay.
A
total
of
59
components
representing
95.9%
of
the
oil
constituents
were
identified which were primarily characterized as 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
also isolated and identified from the MeOH extract. The results of DPPH assays showed that the
essential oil of E. azerbaijanica possessed weak free radical scavenging activity whereas the MeOH
extract and its pure constituents showed significant scavenging activities in comparison with
positive controls. |