Essential Oils of Phlomis persica Boiss. and Phlomis olivieri Benth. from Iran

Journal of Essential Oil Research: JEOR, Nov/Dec 2005 by Khalilzadeh, Mohammad A, Rustaiyan, Abdolhossein, Masoudi, Shiva, Tajbakhsh, Mahmoud

Abstract

The water-distilled essential oils from aerial parts of Phlomis persica Boiss. and Phlomis olivieri Benth., which are endemic to Iran, were analyzed by GC and GC/MS. The oil of P. persica was found to contain germacrene D (38.2%), bicyclogermacrene (16.3%) and &-pinene (13.3%) as major constituents. The oil of P. oliveri was characterized also by higher amount of germacrene D (26.4%) and bicyclogermacrene (12.7%). Both oils consisted mainly of sesquiterpene hydrocarbons.

Key Word Index

Phlomis persica, Phlomis olivieri, Lamiaceae, essential oil composition, germacrene D, bicyclogermacrene, α-pinene.

Introduction

The genus Phlomis is comprised of about 100 species, 17 are described in the flora of Iran, among which 10 are endemic (1,2). In the recent literature the oils composition of P. fruticosa and P. lanata growing in Greece have been published (3,4) while mavonoids (5), iridoids (6) and phenylpropanoidglycosides (7) have been reported from other species of the genus.

In the framework of the studies of essential oils of Iranian plants, especially endemic ones, we report in this study the chemical constituents of the essential oils obtained from the aerial parts of Phlomis persica and P. olivieri.

Experimental

Plant material: The aerial parts of two Phlomis species were collected during the flowering stage at the following places: Phlomis persica growing wild in Taleghan area, north of Tehran and Phlomis olivieri from Khouramabad, Province of Lorestan, Iran, in June 2002. Voucher specimens have been deposited at the Herbarium of the Research Institute of Forests and Rangelands (TARI), Tehran, Iran.

Extraction of the oils: The air-dried aerial parts of both species (150 g and 140 g, respectively) were subjected to separate hydrodistillation using a Clevenger-type apparatus for 3 h, to produce light yellow oils in 0.9% and 0.8% (w/w) yields, respectively.

Analysis: GC analysis was performed on a shimadzu 15 A gas chromatograph equipped with a split/splitless injector (250°C) and a flame ionization detector (250°C). N^sub 2^ was used as carrier gas (1 mL/min) and the capillary column used was DB-5 (50 m x 0.2 mm, film thickness 0.32 µm). The column temperature was kept at 60°C for 3 min and then heated to 220°C with a 5°C /min rate and kept constant at 220°C for 5 min.

GC/MS: Analysis was performed using a Hewlett- Packard 5973 with a HP- 5 MS column (30 m x 0.25 mm, film thickness 0.25 µm). The column temperature was kept at 60°C for 3 min and programmed to 220°C at a rate of 5°C /min, and kept constant at 220°C for 3 min. The flow rate of helium as carrier gas with (1 mL/min). MS were taken at 70 eV. Identification of the constituents of each oil was made by comparison of their mass spectra and retention indices (RI) with those given in the literature and those authentic samples (8). Relative percentage amounts were calculated from peak area using a Shimadzu C- R4 A chromatopac without the use of correction factors.

Results and Discussion

The composition of the essential oils of Phlomis persica and P. olivieri is listed in Table I, in which the percentage and retention indices of components are given. As it is shown, about 97.4% (23 components) of the oil of P. persica and 83.6% (16 components) of the oil of P. olivieri were identified. The oil of P. persica consisted of eight monoterpene hydrocarbons (23.7%), 12 sesquiterpene hydrocarbons (71.2%) and three oxygenated sesquiterpenes (2.5%). Germacrene D (38.2%), bicyclogermacrene (16.3%) and α-pinene (13.3%) were the major components in this oil, followed by germacrene B (8.8%) and limonene (6.0%). The oil or P. olivieri consisted of two monoterpene hydrocarbons (11.4%), nine sesquiterpene hydrocarbons (60.3%), two oxygenated sesquiterpenes (5.6%) and three aliphatic hydrocarbons (6.3%). The major components of this oil were germacrene D (26.4%) and bicyclogermacrene (12.7%) followed by α-pinene (7.7%), germacrene B (5.9%), (E)-9-epi caryophyllene (5.4%), spathulenol (4.7%) and β-bourbonene (4.0%). As can be seen from the above information, both oils are rich in sesquiterpene hydrocarbons (71.2% and 60.3%, respectively). The dominant compounds in the oil of the flowers of P. fruticosa from Greece, were germacrene D (17.8%), γ-bisabolene (12.6%), α-pinene (8.9%) and β-caryophyllene (8.7%) (3). The oil of P. lanata, growing in Greece, contained α-pinene (25.4%), limonene (15.7%) and β-caryophyllene (8.8%) as major components (4).

Acknowledgments

The authors are thankful to the research council of Mazandaran University for partial financial support. We are also grateful to V. Mozaffarian (Research Institute of Forests and Ranpelands, Tehran) for helpful assistance in botanical identification.

References

1. K.H. Rechinger, Phlomis. In: Flora Iranica, Labiatae, No. 150. Edits., K.H. Rechinger and I.C. Hedge, pp 298, 310, Akademische Druck and Verlagsanstalt, Graz, Austria (1982).

2. V. Mozatfarian, A Dictionary of Iranian Plant Names. p 406, Farhang Moaser Publishers, Tehran, Iran (1996).