Abstract:
Lemon verbena (Lippia
citriodora H.B.K., Verbenaceae family) is
indigenous to South America and cultivated
as an aromatic plant in various parts of
world. Lemon thyme (Thymus citriodorus
L.), Lamiaceae family, is a perennial
medicinal plant native to southern Europe
and is cultivated in the Mediterranean
region. These species are cultivated mainly
for the lemon-like aroma emitted from their
leaves due to the presence of dimethyl-2,6-
octadienal, also known as lemonal or citral,
which is used in food and perfumery for its
citrus effect. The aim of this study was to
determine the mineral content and essential
oil components of L. citriodora and
T. citriodorus plants grown under semi-arid
climatic conditions in Turkey. The aerial
parts of lemon thyme and lemon verbena
plants were extracted using hydrodistillation.
The essential oil composition
was analyzed by gas chromatography-mass
spectrometry (GC-MS) and the
microelement contents of the herbs were
examined via inductively coupled plasmaoptical
emission spectrometry (ICP-OES).
The microelement contents were 0.249,
1.630, 16.41, 0.106, and 13.1-36.2 mg kg-1
for cadmium (Cd), copper (Cu), iron (Fe),
and manganese (Mn), respectively, in lemon
thyme, and 0.275, 4.584, 248.1, 15.71, and
1.803 mg kg-1 for Cd, Cu, Fe, Mn, and zinc
(Zn), respectively, in lemon verbena. Fifty
compounds were identified in lemon
verbena essential oil, including limonene
(30.33%), trans-citral (17%), cis-citral
(12.77%), caryophyllene oxide (5.71%), and
geraniol acetate (4.02%) that together
constituted 99.86% of the oil composition.
We also identified 22 compounds
constituting approximately 85.11% of
lemon thyme essential oil, including transgeraniol
(30.07%), trans-citral (15.06%),
cis-citral (11.71%), cis-geraniol (7.65%),
and 3-octanol (6.18%).
