Composition of Thymus serpyllum L. Oil, The
The essential oils isolated by steam distillation from the aerial parts of Thymus serpyllum, before flowering and at full flowering stage were analyzed by capillary GC and GC/MS. Among the 34 compounds identified, the major components were [gamma]-terpinene (21.9% and 22.7%), p-cymene (21.1% and 20.7%), thymol (18.7% and 18.7%) and germacrene D (6.0% and 5.1%) before flowering and at full flowering stage, respectively.
Key Word Index
Thymus serpyllum, Lamiaceae, essential oil composition, [gamma]-terpinene, p-cymene, thymol.
Thymus serpyllum L.
Plant materials were collected from the National Botanical Garden of Iran (Tehran Province) before flowering and full flowering stage in April 2000. A specimen has been deposited in the Herbarium of Research Institute of Forests and Rangelands (TARI).
Dried aerial parts ( 100 g, three times) were steam distilled for 90 min in an all-glass apparatus to produce a yellow oil in yields of 0.57% w/w (before flowering) and 0.90% w/w (full flowering). The oils were dried over anhydrous calcium chloride and stored in sealed vials at a low temperature prior to analysis.
The genus of Thymus presents 14 species which are found wild in different regions of Iran (1), four of which are endemic. We have studied some of the endemic and non-endemic (cultivated) Thymus species previously (2-5). In this paper, we introduce the oil composition of T. serpyllum, which was cultivated in Iran.
The chemical composition, thymol and carvacrol content, insecticidal and antimicrobial effect of T. serpyllum oil have been the subject of previous study (6-12). A comparison between the oil and supercritical carbon dioxide extract of Hungarian T. serpyllum has also been reported (13).
The oils from the aerial parts of T. serpyllum, before and during full flowering stage were investigated by capillary GC and GC/MS. GC analysis was performed using a Shimadzu GC-9A equipped with a DB-I column (60 m × 0.25 mm, 0.25 µm film thickness). Oven temperature was held at 50°C for 5 min and then programmed to 250°C at a rate of 4°C/min, injector and detector (FID) temperature were 260°C, carrier gas was helium with a linear velocity of 32 cm/s. GC/MS analysis was carried out on a Varian 3400 GC/MS system equipped with a DB-I fused silica column (60 m × 0.25 mm); oven temperature, 50°-250°C at a rate of 4°C/min, transfer line temperature 260°C, carrier was helium with a linear velocity of 31.5 cm/s; split ratio 1/60; ionization energy 70 eV; scan time 1 s; mass range 40-300 amu.
The list of the constituents identified can be seen in Table I. They were identified by comparison of their mass spectra with those in the computer library or with authentic compounds. The identifications were confirmed by comparison of their retention indices either with those of authentic compounds or with data in the literature (14,15). Thirty compounds were identified in the oil of T. serpyllum before flowering, representing 98.0% of the oil, while 32 compounds were found in the oil during the full flowering stage, representing 88.1% of the oil. The major components were [gamma]-terpinene (21.9% and 22.7%), p-cymene (21.1% and 20.7%), thymol (18.7% and 18.7%) and germacrene D (6.0% and 5.1%) before flowering and during full flowering stage, respectively.
As shown in Table I, the percentage of p-cymene, [gamma]-terpinene, thymol, germacrene D and many other constituents in the oil of T. serpyllum are very similaar before and during the full flowering stage. An exeption can be seen in [beta]-caryophyllene which was found in the oil obtained before flowering 7.1%, while at full flowering stage it was a minor (0.1%) constituent.
The content of thymol and carvacrol found in our oil of T. serpyllum was less than in other species found in Iran (2-5).
The authors would like to acknowledge the financial support provided by the Research Institute of Forests and Rangdamls forth is work. We thank from Dr. Mirzei and M.S. Barazandehfor injection of the oils to GC/MS and GC.
1. V. Mozaffarian, A Dictionary of Iranian Plant Names. Farhang Moaser.Tehran, Iran (1996).
2. F. Sefidkon, Z. Jamzad, R. Yavari and D. Nouri Shargh, Essential oil composition of Thymus kotschyanus Boiss & Hohen from Iran. J. Essent. oil Res., 11, 459-460 (1999).
3. F. Sefidkon, F. Askari and A. Mirmostafa, The essential oil of Thymus carnosus Boiss. from Iran. J. Essent. oil Res., accepted for publication.
4. F. Sefidkon, M. Dabiri and A. Mirmostafa, Essential oil of Thymus persicus (Honniger ex Rech. F.) Jalas from Iran. J. Essent. oil Res., accepted for publication.
5. F. Sefidkon, M. Ghorbanli and F. Askari, Essential oil composition of Thymus pubescens Boiss & Kotschy ex Celak from Iran. J. Essent. oil Res., accepted for publication.
6. S.V. Sur, P.M. Tulyupa, A. Ya. Tolok and T.N. Peresypkina, Gas-liquid Chromatographie determination of thymol and carvacrol in raw plant material and tinctures of Thymus herb. Khim.-Farm. Zh., 24(10), 69-71 (1990).
7. C.R. Roger, A. Hamraoui, M. Holeman.E.Theronand R. Pinel, Insecticidal effect of essential oils from Mediterranian plants on Acanthoscelides obtectus Say, a pest of Kidney bean. J. Chem. Ecol., 19, 1233-1244 (1993).
8. I. Uchama, M. Furuhata and M. Yasuda, Bath preprations containing antimicrobial medicinal plant extracts and astringent compounds. Jpn. Kokai Tokkyo Koho, JP 09 02,941 [97 02,941 ]; Chem Abst. 126,176656 (1997).
9. K. Loziene, J. Vaiciuniene, P.R. Venskutonis, Chemical composition of the essential oil of creeping thym (Thymus serpyllum s.l.) growing wild in Lithuania. Planta Med., 64, 772-773 (1998).
10. B.M. Lawrence, Progress in essential oils. Perfum. Flavor., 6(5), 27-34 (1981); 23(3), 63-82 (1998).
11. A. Sattar, M.S. Malik, S.A. Khan, Essential oils of the species of Labiatae. Pak. J. Sei. Ind. Res., 34, 119-120(1991).
12. C. Juliano, A. Mattana, M. Usai, Composition and invitro antimicrobial activity of the essential oil of Thymus herba-barona Loisel growing wild in Sardinia. J. Essent. oil Res., 12, 516-522 (2000).
13. M. Oszagyan, B. Simandi, J. Sawinsky and A. Kery, A comparison between the oil and supercritical carbon dioxide extract of Hungarian wild Thyme. J. Essent. oil Res., 8, 333-335 (1996).
14. N.W. Davies, Gas Chromatographie retention indices of monoterpenes and sesquiterpenes on methyl silicone and Carbowax 2OM phases. J. Chromatogr., 503, 1-24 (1990).
15. T. Shibamoto, Retention Indices in Essential oil Analysis, In: Capillary Gas Chromatographyin Essential oil Analysis, Edits., P. Sandra and C. Bicchi, Chapter 8, pp 259-274, Alfred Huethig Verlag, New York (1987).
Research Institute of Forests and Rangelanch, P.O. Box 13185-116, Tehran, Iran
M. Dabiri and S.A. Mirmostafa
Shahid Beheshti University, Faculty of Science, Chemistry Department, Tehran, Iran
* Address for correspondence
Received: May 2001
Revised: May 2001
Accepted: June 2001
1041-2905/04/0003-0184$6.00/0-©2004 Allured Publishing Corp.
Copyright Allured Publishing Corporation May/Jun 2004
Provided by ProQuest Information and Learning Company. All rights Reserved