Volatile Oils of Ducrosia assadii Alava. and Prangos acaulis (DC.) Bornm. from Iran

Journal of Essential Oil Research: JEOR, Nov/Dec 2006 by Rustaiyan, Abdolhossein, Mazloomifar, Hefzollah, Masoudi, Shiva, Aghjani, Zahra

Abstract

The water distilled oils from the aerial parts of Ducrosia assadii Alava., endemic in Iran, and Prangos acaulis (DC.) Bornm. were analyzed by GC and GC/MS. Decanal (36.4%) was the main components among the 29 constituents characterized in the oil of D. assadii, representing 88.3% of the total components detected. Twenty-three compounds were identified in the oil of P. acaulis, representing 90.0% of the total oil, with cis-sesquisabinene hydrate (25.6%) and α-pinene (12.5%) as main constituents.

Key Word Index

Ducrosia assadii, Prangos acaulis, Umbelliferae, essential oil composition, decanal, cis-sesquisabinene hydrate, α-pinene.

Introduction

The genus Ducrosia is represnted in Iran by three species: D. assadii Alava., D. flabellifolia Boiss. and D. anethifolia (DC.) Boiss., of which D. assadii and D. flabellifolia are endemic plants (1,2). A few reports on the analysis of the essential oils of Ducrosia species have been published. For example, the oil of Ducrosia ismael was found to contain myrcene, undecane, α-pinene, butylbenzene, δ-cadinene, 3,5-dimethyl styrene, 5-methyl indane, p-menthadiene, cymene, γ-terpine, sabinene, decanol and fenchone as the major constituents (3).

The herb oil of D. anethifolia growing in Iran contained α-pinene, myrcene and limonene as main monoterpene hydrocarbons while decanal, dodecanal, decanol, (E)-2-decenal and cis-chrysanthenyl acetate were the major oxygen-containing constituents. The oil and the main oxygenated containing aliphatic components showed a remarkable antimicrobial activity against Gram-positive bacteria, a yeast and some dermatophytes (4).

Fifteen species of the genus Prangos are found in Iran, among which five are endemic (1,2). Chemical investigation of some Prangos species have shown the presence of coumarins (5,6). The water distilled oil obtained from the aerial parts of P. latiloba has been the subject of our previous studies. The major components were identified to be α-pinene (25.1%), limonene (16.1%) and myrcene (9.5%) (7).

Baser et al. reported that the oils from crushed dry fruits of P. heyniae from two localities in Turkey, contained β-bisabolenal (53.3% and 18.0%), β-bisabolenol (14.6% and 2.3%) and β-bisabolene (12.1% and 10.1%) as main constituents. Germacrene D (13.5%) and germacrene B (9.4%) were also main components in one of the samples (8).

The composition of the oils obtained by steam distillation of the aerial parts and hydrodistillation of seed of P. uloptera, growing in Iran, have been reported. The main constituents of the oil of the aerial parts were β-caryophyllene (18.2%), germacrene D (17.2%) and limonene (8.7%), whereas the seed oil comprised mainly α-pinene (41.9%) and β-cedrene (4.0%) (9).

A literature survey revealed that the oils of D. assadii Alava and P. acaulis (DC.) Bornm. have not been previously studied, so we decided to examine them.

Experimental

Plant material: The aerial parts of D. assadii Alava. (180 g) was collected during the flowering period from Bakrii Village, altitude 1900 m, Provonce of Kerman, in July 2002. The aerial parts of P. acaulis (DC.) Bornm. (syn: P. szovitsii Boiss, P. odontoptera Boiss. and P. cinerea Bioss.) (190 g) was collected from Damavand, north of Tehran, in June 2003 during the flowering period.

Voucher specimens (No. 2834 and 6008, respectively) were deposited at the Herbarium of the Research Institute of Forests and Rangelands (TARI) in Tehran, Iran.

Oil isolation: Air-dried arial parts of D. assadii and P. acaulis were ground, and the oils isolated by hydrodistillation for 3 h using a Clevenger-type apparatus. After decanting and drying over anhydrous sodium sulfate, the corresponding yellowish colored oils were recovered in a yield of 0.4% and 0.82% (w/w), respectively.

Analysis: GC analysis was performed in a Shimadzu GC-15A 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). The capillary column used was DB-5 (50 m x 0.2 mm, film thickness 0.32 pm). 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. Relative percentage amounts were calculated from the peak area using a Shimadzu C-R4A chromatopac without the use of correction factors.

GC/MS analysis was performed using a Hewlett-Packard 5973 with an HP-5MS column (30 m x 0.25mm, film thickness 0.25 pm). 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 carrier gas was He, with a flow rate of 1 mL/min). MS were taken at 70 eV. Identification of the constituents of each oil was made by comparision of their mass spectra and retention indices (RI) with those given in the literature and those authentic samples (10).

Results and Discussion

The composition of the oils of D. assadii and P. acaulis are given in Table I and II, respectively. In D. assadii oil, 29 components representing about 88.3% of the total composition of the oil were identified. The oil of D. assadii consisted of six monoterpene hydrocarbons (8.7%), nine oxygenated monoterpenes (16.9%), five oxygenated sesquiterpenes (5.9%), three aliphatic aldehydes (45.1%) and six aliphatic compounds (11.7%). Decanal (36.4%) was found to be the major component in this oil, followed by dodecanal (8.1%), cis-chrysanthenyl acetate (6.7%), decanol (6.6%) and linalool (6.1%). Furthermore, 23 components in the oil of P. acaulis, representing 90.0% of the total oil, were identified. The oil of P. acaulis consisted of eight monoterpenes (20.3%), seven sesquiterpenes (48.2%), one aliphatic acid (0.2%) and one oxygenated diterpene (5.6%). The major components in this oil were cis-sesquisabinene hydrate (25.6%) and α-pinene (12.5%), followed by γ-eudesmol (7.4%), spathulenol (7.2%), β-elemene (6.8%) and phytol (5.6%). As can be seen from the above information, the composition of both oils were different qualitatively and quantitatively.