Iranian Journal of Pharmaceutical Research (2007), 6 (2): 135-140
Received: October 2005
Accepted: June 2006
Copyright © 2007 by School of Pharmacy
Shaheed Beheshti University of Medical Sciences and Health Services
Short Communication
Chemical Composition of the Essential Oils of Four Cultivated
Eucalyptus Species in Iran as Medicinal Plants
(E. microtheca, E. spathulata, E. largilorens and E. torquata)
Fatemeh Seidkon*, Mohammad Hassan Assareh, Zahra Abravesh
and Mohammad Mehdi Barazandeh
Research Institute of Forests and Rangelands,Tehran, Iran.
Abstract
The leaves of four cultivated Eucalyptus species, Eucalyptus microtheca var. Microtheca F.
Muell., Eucalyptus spathulata, Eucalyptus largilorens and Eucalyptus torquata were collected
in spring from Kashan and Isfahan provinces (central region of Iran). After drying the plant
materials in shade, their essential oils were obtained by hydro-distillation. The oils were analyzed
by capillary gas chromatography, using lame ionization and mass spectrometric detection.
Twenty-two components were identiied in the oil of Eucalyptus microtheca with 1,8-cineole
(34.0%), p-cymene (12.4%), α-pinene (10.7%) and β-pinene (10.5%) as main constituents.
Twenty-one compounds were identiied in the oil of Eucalyptus spathulata with 1,8-cineole
(72.5%) and α-pinene (12.7%) as main components. Twenty-six compounds were characterized
in the oil of Eucalyptus largilorens with 1,8-cineole (37.5%), p-cymene (17.4%) and neoisoverbenol (9.1%) as main components. Sixteen compounds were characterized in the oil of
Eucalyptus torquata with 1,8-cineole (66.9%) α-pinene (13.9%) and trans-pinocarveol (6.3%)
as main constituents. The results showed that although the 1,8-cineole was the main component
of the essential oils of all Eucalyptus species, but its relative content was higher in the oil of
Eucalyptus spathulata and Eucalyptus torquata.
Keywords: Eucalyptus microtheca; Eucalyptus spathulata; Eucalyptus largilorens,
Eucalyptus torquata.
Introduction
There are over 700 different species of
Eucalyptus in the world, of which at least 500
produce a type of essential oil. The leaves and oils
of many Eucalyptus species are especially used
for respiratory aliments such as bronchitis and
croup (1-4) and the dried leaves are smoked like
tobacco for asthma in some countries. Some of
the Eucalyptus species are also used for feverish
* Corresponding author:
E-mail:frsef@rifr.ac.ir
conditions e.g.(malaria, typhoid, cholera) and
skin problems like burns, ulcers and wounds
(5). Aqueous extracts are used for aching joints,
bacterial dysentery, ringworms, tuberculosis,
etc. They are applied for similar reasons in both
western and eastern medicine. The Eucalyptus
oils and their main component (1,8-sineole)
are largely used in the preparation of liniments,
inhalants, cough syrups, ointments, toothpaste
and also as pharmaceutical lavours in veterinary
practice and dentistry. While being used as
fragrance component in soaps, detergents and
toiletries, they have little use as perfumes. The
Seidkon F, Assareh MH, Abravesh Z and Barazandeh MM / IJPR (2007), 6 (2): 135-140
oils of Eucalyptus species have also antioxidant
properties (6) and anti-inlammatory effects (78) because of 1,8-cineole.
The European Pharmacopoeia monograph
for Eucalyptus oil speciies a chromatographic
proile: 1,8-cineole (=eucalyptol; not less than
70%), limonene (4- 12%), α-pinene (2-8%), αphellandrene (less than 1.5%), β-pinene (less
than 0.5%), camphor (less than 0.1%) (9).
To meet these requirements and to minimize
less desirable substances such as aldehydes,
the oil obtained from initial steam distillation
is rectiied by alkaline treatment and fractional
distillation. The rectiied oil contains 70-90%
of 1,8-cineole (10-12). Sesquiterpenes such as
globulol and aromadendrene, which are usually
present in unrectiied, steam-distilled oil (13),
were not detected in the rectiied oils.
In this study the essential oils of four
cultivated and adapted Eucalyptus species in
warm regions of Iran were investigated for their
essential oil content and composition. We have
also reported the oil content and composition
of ive other cultivated Eucalyptus species from
these locations previously (14).
There are many references about the
composition of other Eucalyptus species in
the literature. For example, the essential oils
obtained by steam distillation from the leaves of
nine Eucalyptus species (E. cinerea F. Muell., E.
baueriana F. Muell., E. smithii R. T. Baker, E.
bridgesiana R. T. Baker, E. microtheca F. Muell.,
E. foecunda Schau., E. pulverulenta Sims, E.
propinqua Deane and Maiden, E. erythrocorys F.
Muell.) of Moroccan origin have been analyzed
using GC and GC-MS. A total of 83 constituents
were identiied. All the species investigated
were found to possess an oil rich in 1,8-cineole
(>68%). In ive species (E. cinerea F. Muell., E.
baueriana F. Muell., E. smithii R. T. Baker, E.
bridgesiana R. T. Baker and E. microtheca F.
Muell.), the 1,8-cineole content exceeded 80%
(15).
The volatile oils of leaves of Eucalyptus
nutans, E. platypus Hook. var. platypus, E.
platypus Hook. var. heterophylla Blakely, E.
spathulata Hook. subsp. spathulata, E. spathulata
Hook. subsp. grandilora (Benth.) L.A.S. Johnson
and D.F. Blaxell, E. steedmanii C.A. Gardner, E.
eremophila (Diels) Maiden subsp. eremophila,
E. salubris F. Muell. subsp. salubris, E. ravida
L.A.S. Johnson and K.D. Hill, E. campaspe S.
Moore, E. diptera C.R.P. Andrews, E. terebra
L.A.S. Johnson and K.D. Hill, E. doratoxylon
F. Muell., and E. decurva F. Muell, isolated
by vacuum distillation, were analysed by GC
and GC-MS. All species contained α-pinene
(2.8-32.5%), 1,8-cineole (8.2-51.2%), p-cymene
(0.3-3.3%), aromadendrene (2.3-19.0%) and
bicyclogermacrene (0.3-28.6%) as principal leaf
oil components (16).
During the period 1995-1997, the essential
oils of leaves of 16 taxa of Eucalyptus had
monitored to see if their oil compositions were
essentially stable. These species were Eucalyptus
tumida Brooker & Hopper; Eucalyptus
histophylla Brooker & Hopper; Eucalyptus
lavida Brooker & Hopper; Eucalyptus clivicola
Brooker & Hopper; Eucalyptus varia Brooker
& Hopper subsp. varia; Eucalyptus varia
Brooker & Hopper subsp. salsuginosa Brooker
& Hopper; Eucalyptus angustissima F. Muell.
subsp. angustissima; Eucalyptus balladoniensis
Brooker subsp. balladoniensis; Eucalyptus
cyclostoma Brooker; Eucalyptus aequioperta
Brooker & Hopper; Eucalyptus species aff.
pileata (E. sp. U in Brooker & Kleinig);
Eucalyptus species aff. dumosa; Eucalyptus
calcicola Brooker; Eucalyptus ligulata Brooker;
Eucalyptus aquilina Brooker and Eucalyptus
preissiana Schauer subsp. lobata Brooker &
Slee. The main components in the oils were
torquatone, bicyclogermacrene and 1,8-cineole.
The results indicate that during the period of
observation, the compositions of all the essential
oils were quite stable, except for two species
which exhibited a seasonal variation. By March
1997, all taxa had generated buds and six had
lowered (17).
Experimental
Materials and Methods
Plant Material
The seeds of some Eucalyptus species (Origin:
Australia) were cultivated in the years 19931994 in Kashan in the central region of Iran.
Some of these species have good adaptability
with the climatic condition of Kashan (Hot and
dry weather). The fresh leaves of four adapted
136
Chemical composition of the essential oils of four Cultivated Eucalyptus species in Iran
Table 1. Plant materials used for this study
Eucalyptus species were collected in the middle
of spring (2005), as mentioned in Table 1. The
voucher specimens have been deposited in the
national herbarium of Iran (TARI).
indices either with those of authentic compounds
or with data published in the literature (18- 19).
The retention indices were calculated for all
volatile constituents using a homologous series
of n-alkanes.
Isolation procedure
Air-dried leaves of the plants (50-70 g, three
times) were subjected to hydro-distillation for
2.5h using a Clevenger-type apparatus. The oils
separated from water and dried over anhydrous
sodium sulfate and stored in sealed vials at low
temperature before analysis.
Results and Discussion
The oils isolated by hydro-distillation from the
leaves of Eucalyptus microtheca var. microtheca
F. Muell., Eucalyptus spathulata, Eucalyptus
largilorens and Eucalyptus torquata were found
to be colorless to pale yellow liquids. These oils
were analyzed by capillary gas chromatography,
using lame ionization and mass spectrometric
detection. The mean oil yields of each species
are shown in Table 1.
Twenty-two components were identiied in
the oil of Eucalyptus microtheca. The major
components were 1,8-cineole (34.0%), p-cymene
(12.4%), α-pinene (10.7%), β-pinene (10.5%)
and virdilorene (5.2%). Twenty-one compounds
were identiied in the oil of Eucalyptus
spathulata. The main components of this oil
were 1,8-cineole (72.5%), α-pinene (12.7%) and
trans-pinocarveol (3.3%. Twenty-six compounds
were characterized in the oil of Eucalyptus
largilorens. The main components of this oil
were 1,8-cineole (37.5%), p-cymene (17.4%),
neo-isoverbenol (9.1%), limonene (6.5%) and
terpinen-4-ol (3.6%). Sixteen compounds were
characterized in the oil of Eucalyptus torquata.
The main components of this oil were 1,8-cineole
(66.9%) α-pinene (13.9%), trans-pincarveol
(6.3%) and p-cymene (4.2%).
The chemical composition of the oils can be
seen in Table 2. The components are listed in the
order of their elution on the DB-5 column.
The results showed that although 1, 8-cineole
was the main component of the essential oils of
all Eucalyptus species, but its relative amount in
GC and GC/MS analysis
The oils obtained from three distillation of each
Eucalyptus species were mixed and then injected
to GC and GC/MS. GC analyses were performed
using a Shimadzu GC-9A gas chromatograph
equipped with a DB-5 fused silica column (30
m x 0.25 mm i.d., ilm thickness 0.25 µm). Oven
temperature was was programmed to be held at
40°C for 5 minutes and then increased to 280 °C
at a rate of 4 °C/min.. Injector and detector (FID)
temperatures were 290 °C, and helium was used
as carrier gas with a linear velocity of 32 cm/s,
and split ratio 1/60.
GC-MS analyses were carried out on a
Varian 3400 GC-MS system equipped with
a DB-5 fused silica column (30 m x 0.25 mm
i.d.). Oven temperature was 40 °C increasing to
250°C at a rate of 4°C, transfer line temperature
260°C. The carrier gas was helium with a linear
velocity of 31.5 cm/s, split ratio 1/60, Ionization
energy 70 eV, scan time1 s and mass range of
40-300 amu. The percentages of compounds
were calculated by the area normalization
method, without considering response factors.
The components of the oils were identiied by
comparison of their mass spectra with those of a
computer library or with authentic compounds,
and conirmed by comparison of their retention
137
Seidkon F, Assareh MH, Abravesh Z and Barazandeh MM / IJPR (2007), 6 (2): 135-140
Table 2. Percentage composition of the oils of Eucalyptus species
the oil of E. spathulata was the highest (more
than 70%) and in the oil of E. microtheca the
lowest (34.0%). In addition, there are some
other differences and similarity between oil
compositions of these Eucalyptus species.
The percentage of α-pinene in the oils of E.
138
Chemical composition of the essential oils of four Cultivated Eucalyptus species in Iran
largilorens was 2.4%, while in other oils it
was more than 10%. The oil of E. largilorens
contained limonene (6.5%), neo-isoverbenl
(9.1%) and spathulenol (6.7%) as well, while
these compounds were not found in other oils or
were found at lower amounts. The contents of
p-cymene in the oils of E. mictotheca (12.4%)
and E. largilorens (17.4%) were higher than two
other oils
Comparing these results with those of ive
Eucalyptus oils studied previously (14), showed
the 1,8-cineol percentage of E. spathulata oil
(72.5%) is comparable with 1,8-cinele in the oil
of E. intertexta (81.5%), E. leucoxylon (85.5%)
and E. sargentii (77.2%).
It can be concluded that the highest oil yield
was obtained for E. spathulata (1.88% w/w) and
the lowest for E. microtheca (0.38%). Statistical
data showed no signiicant difference between oil
yields of E. spathulata and E. torquata. 22, 21,
26 and 16 compounds were identiied in the oils
of E. microtheca, E. spathulata, E. largilorens
and E. torquata, respectively that approximately
constitute 99.1%, 98.7%, 98.4% and 98.8% of
the oils, in the mentioned order.
The high amounts of 1, 8-cineole in the oils
of E. torquata and E. spathulata is remarkable.
1,8-Cineole, which is a terpenoid oxide present
in many plant essential oils, displays an
inhibitory effect on some types of experimental
inlammation in rats, i.e. paw oedema induced
by carrageenan and cotton pellet-induced
granuloma. It has anti-microbial, antiinlammatory and anti-nociceptive effects (78). So it can be concluded that the oils of these
two Eucalyptus species could have the medicinal
properties, which should be investigated in other
studies.
Eucalyptus spathulata with 1.88% oil and
72.5% 1, 8-cineole is suggested as a good source
for medicinal uses. According to the European
Pharmacopoeia, it has the most desirable
speciications, i.e. 72.5% of 1,8-cineole (not
less than 70%), α-phellandrene (0.1%, less
than 1.5%), β-pinene (0.4%, less than 0.5%),
camphor (0.0%; less than 0.1%). Of course,
the percentage of α-pinene (12.7%) is high
and limonene (1.1%) is low. So, it needs minor
rectiication or fractional distillation. In addition,
the time of sampling was before lowering. The
authors will investigate the oils in other seasons
to ind the best time of harvesting for obtaining
the best quantity and quality of the oils. In
addition, the oil of E. torquata could also be used
for medicinal uses with minor rectiication.
The essential oils of other Eucalyptus species
studied contained low amounts of 1,8-cineole
according to the European Pharmacopoeia.
References
(1) Kaspar P, Repges R, Dethlefsen U and Petro W.
Sekretolytika im vergleich. anderung der ziliarfrequenz
und lungen function nach thrapie mit cineol und
ambroxol. Atemw Lungenkrkh. (1994) 20: 605-14
(2) Wittman M, Petro W, Kaspar P, Repges R and Dethlesten
U. Zur thrapie chronisch obstruktiver atemwegserkrankungen
mit
sekretolytika.
doppelblinder,
randomisierter cross-over-vergleich zwischen cineol
und ambroxol. Atemw Lungenkrkh. (1998) 24: 67-74
(3) Mahlo DH. Obstruktive atemwegserkrankungen
mit cineol die lungenfunktionsparameter verbesern.
Therapiewoche (1990) 40: 3157-62
(4) Juergens UR, Stober M and Vetter H. Steroidartige
hemmung
des
monozytaren
arachidonsaure
metabolismus und der 1l-1β-produktion durch 1,8cineole. Atemw Lungenkrkh (1998) 24: 3-11
(5) Reynolds JEF and Prasad AB. (Eds.) Martindale-The
Extra Pharmacopoiea. 28th ed. Pharmaceutical Press,
London (1982) 1017-8
(6) Grassmann J, Hippeli S, Dornisch K, Rohnert U,
Beuscher N and Elstner EF. Antioxidant properties
of essential oils. Possible explanations for their antiinlammatory effects. Arzneim Forsch/Drug Res.
(2000) 50: 135-139
(7) Juergens UR, Dethlefsen U, Steinkamp G, Gillissen A,
Repges R and Vetter H. Anti-inlammatory activity of
1,8-cineole (eucalyptol) in bronchial asthma: a double
blind placebo-controlled trial. Respiratory Med. (2003)
97: 250-6
(8) Santos FA and Rao VS. Anti-inlammatory and
antinociceptive effects of 1,8-cineole, a terpenoid
oxide present in many plant essential oils. Phytother
Res. (2000) 14: 240-244
(9) Council of Europe (COE)- European Directorate for the
quality of Medicine (EDQM) European Pharmacopeia,
5th ed. Supplement 5.5,Council of Europe, london, 270
(10) Brand N. Eucalyptus. In: Drogen EO. (Ed.) Hagers
Handbuch der Pharmazeutischen Praxis. 5th ed.
Volume 5, Springer-Verlag, Berlin (1993) 115-130
(11) Harkenthal M, Reichling J, Geiss HK and Saller R.
Comparative study on the in vitro antibacterial activity
of Australian tea tree oil, cajuput oil, niaouli oil,
manuka oil, kanuka oil and eucalyptus oil. Pharmazie
(1999) 54: 460-3
(12) Wilson ND, Watt RA and Moffat AC. A near-infrared
method for the assay of cineole in eucalyptus oil as
an alternative to the oficial BP method. J. Pharm.
139
Seidkon F, Assareh MH, Abravesh Z and Barazandeh MM / IJPR (2007), 6 (2): 135-140
Pharmacol. (2001) 33: 95-102
(13) Renedo J, Otero JA and Mira JR. Huile essentielle
d’Eucalyptus globules L. de cantabrie (Espange).
Variation au cours de la distillation. Planets Med.
Phytother. (1990) 24: 31-5
(14) Seidkon F, Assareh M. H., Abravesh Z and Mirza
M. Chemical composition of the essential oil of ive
cultivated Eucalyptus species in Iran (E. intertextra,
E. platypus, E. leucoxylon, E. sargentii and E.
camaldulensis). J. Essent. Oil Bearing Plants (2006)
9(3) : 245-250
(15) Zrira S, Bessiere JM, Menut C, Elamrani A and Benjilali
B. Chemical composition of the essential oil of nine
Eucalyptus species growing in Morocco. Flav. Fragr.
J. (2004) 19: 172-175
(16) Bignell CM, Dunlop PJ, Brophy JJ and Jackson JF.
Volatile leaf oils of some south-western and southern
australian species of the genus Eucalyptus. Part X.
Subgenus symphyomyrtus, section bisectaria. (a)
Unpublished series erectae, (b) Series contortae and (c)
Series decurvae. Flav. Fragr. J. (1996) 11: 101-106
(17) Nicolle D, Dunlop PJ and Bignell CM. A study of the
variation with time of the compositions of the essential
leaf oils of 16 Eucalyptus species. Flav. Fragr. J.
(1998) 13: 324-328
(18) Adams RP. Identiication of Essential Oil Components
by Gas Chromatography/ Mass Spectroscopy. Allured
Publishing Corp., Carol Stream, (1995)
(19) Shibamoto T. Retention indices in essential oil analysis.
In: Sandra P and Bicchi C. (Eds.) Capillary Gas
Chromatography in Essential Oil Analysis. Huethig
Verlag, New York (1987) 259-274
This article is available online at http://www.ijpr-online.com
140