Abstract: Background: Echinophora orientalis is perennial, crowded and much branched herb distribute from Turkey to Iran and Caucasia. There is no report on essential oil composition of Echinophora orientalis in Iran. However, the chemical composition of the plant oil was determined in Turkey where the main compounds of oil were reported as: Myrcene (34.2%) and p-cymene (18.9%). This study was focused on the composition of the essential oil of Echinophora orientalis leaves. Materials and methods: The powdered air dried of Echinophora orientalis aerial parts were distillated for 3 h by a Clevenger type apparatus. The chemical composition of the hydrodistilled essential oil was analyzed by GC-MS. The oil components were identified by comparison of their RI with those reported in the literature and their mass spectrum was compared with Wiley Library. Results: Totally, 23 compounds were identified comprising 99.9% of the oil. β-myrcene (32.1%) was the main constituent of oil, followed by α-pinene (16.7%) and p-cymene (14.34%). The results showed monoterpenes dominated in leaf oils. Conclusion: The comparison of the result with literature showed the essential oil composition profile of Echinophora orientalis collected from Iran is similar to those of Eastern Turkey. Thus, it is assumed that two samples of Echinophora might be of same chemotype. It was previously shown that β-myrcene has different bioactivities. It was assumed that the oil of E. orientalis might be exhibited various pharmacological and biological properties.
INTRODUCTION
The genus Echinophora (family: Apiaceae) comprised of 10 species distributed from Mediterranean region to Iran and Afghanistan (Georgiou et al., 2010). In flora of Iran the genus is represented by 4 species ie., E. sibthorpiana, E. orientalis, E. platyloba and E. cinerea. Two last species are endemic in Iran (Mozaffarian, 2003). Echinophora orientalis is the common specie of the genus in Iran. It is a perennial, crowded and much branched herb that reaches to 100 cm in height. This herb has small white flowers integrated in dens umbels with flowering period of Jun-July (Ghahreman, 1988). The plant is an Irano-Turano element that grows in clay to loam soils. Echinophora orientalis distribute from Turkey to Iran and Caucasia (Mozaffarian, 2007). In Iran, the plant distribution limited to west and North West provinces, where the plant named as Khosharizeh and Tologh-Oti, respectively. The aerial parts of Echinophora orientalis were used as vegetable for preparation of soup in some parts of Iran. On the other hands, the plant may be used as an animal fodder. In Turkey, as a fragrance agent the plant roots have been added to “helva” a Turkish sweet (Baser et al., 1998). There is no report on essential oil composition of Echinophora orientalis in Iran. However, the chemical composition of the plant oil was determined in Turkey where the main compound of oil were report as: myrcene (34.2%) and p-cymene (18.9%) (Baser et al., 1998).
There are some reports in the literature on biological activity of Echinophora species. Essential oil and extract of E. platyloba aerial parts has antimicrobial, antifungal and antioxidant activity and could be used as a recommended natural substance for food preservation and production of more effective drugs (Gholivand et al., 2011; Avijgan et al, 2006; Avijgan et al., 2010; Entezari et al., 2009; Saei-Dehkordi et al., 2012). Metalonic extract and essential oil of E. cinerea (Boiss.) aerial parts has antineoplastic and antimicrobial activity, respectively (Amirghofran et al., 2006; Teimori, 2010). Essential oil of E. spinosa L. has good antimicrobial and antifungal activity. Antimicrobial activity of this oil was higher than some synthetic commercial drugs (Glamoclija et al., 2011). Essential oil of aerial parts of E.sibthorpiana also showed antimicrobial activity (Kivanc, 1988). This study was focused on the composition of the essential oil of Echinophora orientalis leaves.
MATERIALS AND METHODS
Plant materials: The aerial parts of Echinophora orientalis, were collected at flowering stage from Eastern Azerbaijan province (North-West of Iran) at an altitude of 1550-1555 m in July 2012. A voucher specimen (No. 1391-2) was deposited in the Herbarium of the Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil, Iran.
Essential oil isolation: Air dried leaves of the plant were hydrodistilled for 3h, using a Clevenger type apparatus.
Essential oil analysis: The oils were analyzed by GC-MS. The analysis was carried out on a Thermoquest-Finnigan Trace GC/MS instrument equipped with a DB-5 fused silica column (60x0.25 mm i.d., film thickness 0.25 μm).The oven temperature was programmed to increase from 60 to 250°C at a rate of 5°C min-1 and finally held for10 min; transfer line temperature was 250°C. Helium was used as the carrier gas ata flow rate of 1.1 mL min-1 with a split ratio equal to 1/100. The quadrupole mass spectrometer was scanned over the 35-465 amu with an ionizing voltage of 70 eV and an ionization current of 150 mA.
Identification of essential oil: Retention Indices (RI) were calculated by using retention times of n-alkanes (C6-C24) that were injected after the oil at the same temperature and conditions. Compounds were identified by comparison of their RI with those reported in the literature and their mass spectrum was compared with Wiley Library (Razavi and Nejad-Ebrahimi, 2010).
RESULTS AND DISCUSSION
The hydrodistillation of Echinophora orientalis leaves afforded a greenish yellow oil with a yield of 0.53% (V/W). The identified components and their percentage are given in Table 1, where the components are arranged in order of elution the DB-5 column. Twenty three compounds were characterized representing 99.9% of the oil. The result showed that the oil was dominated by β-myrcene (32.1%), α-pinene (16.7%) and p-cymene (14.34%) as main compounds. The results show that the oil contains Monoterpene (84.82%), Cycloalkene (6.38%), Aliphatic hydrocarbons (6.2%), Oxygenated Monoterpens (2.01%) and Aromatic hydrocarbons (0.58%) (Table 2). Whereas, the oil enriched of monoterpenic compounds, no sesquiterpens was detected in the oil. From these results, it was clear that essential oil of Echinophora orientalis can be regarded as a sesquiterpeneless oil.
The comparison of the results with those of (Baser et al., 1998) showed the essential oil composition profile of Echinophora orientalis collected from Iran is similar to those of Eastern Turkey (Baser et al., 1998). Thus, it is assumed that two samples of Echinophora might be of same chemotype.
A survey literature showed the essential oil composition of some Echinophora species have previously reported. The comparison of the essential oil composition among different species of the genus revealed a considerable variation in the oil profile.
However, based on major component of the essential oil, some species of Echinophora could be classified in 3 groups:
| • | Species with high level of monoterpens such as: | |
| • | E. platyloba and E. cinerea (sisakht mountain of iran chemotype) rich in β-ocimene (Asghari et al., 2010; Mazloomifar et al., 2004; Hassanpouraghdam et al., 2009; Rahimi-Nasrabadi et al., 2010; Teimori, 2010) | |
| • | E. orientalis rich in β-myrcene (Baser et al., 1998) | |
| • | E. trichophylla rich in sabinene (Baser et al., 1998) | |
| • | E. chrysantha, E. cinerea (west and south west of iran chemotype), E. sibthorpiana (west of Turkey and Greece chemotype) and E. spinosa rich in α-phellandrene (Baser et al, 1996; Ahmadi et al., 2001; Sajjadi and Ghannadi, 2002; Pass et al., 2012; Baser et al., 1994; Georgiou et al., 2010; Margaris et al., 1982) | |
| • | E. sibthorpiana (north of iranchemotype), E. spinosa (Serbia chemotype) and E. lamondiana rich in δ-carene (Glamoclija et al., 2011; Sefidkon, 2004; Baser et al., 2000) | |
| • | Species with high level of sesquiterpens such as: |
| • | E. carvifolia and E. tournefortii were characterized by Germacrene and Caryophyllene oxide, respectively (Baser et al., 1998) |
| • | Species with high level of phenylpropene such as: |
| • | E. sibthorpian rich in Methyl eugenol (Baser et al., 1998; Ahmad et al., 1999; Ozcan et al., 2002) |
β-myrcene, the major compound of E. orientalis leave essential oil is considered as an acyclic unsubstituted monoterpene with a peppery spicy or balsam odor. In commercial production β-myrcene is used as intermediates in the production of terpene alcohols such as geraniol, nerol and linalool which, in turn, serve as intermediates in the production of aroma and flavor chemicals. The compound has been used in the production of cosmetics, soap and detergents. It is regarded as a flavoring agent in food and beverages, as well as. Furthermore, β-myrcene is the major constituent of hop and bay oils which are used in the manufacture of alcoholic beverages. β-myrcene is the chief ingredient in lemongrass tea used in Brazilian folk medicine to treat gastrointestinal disturbances, a sedative and antipyretic. It acts as a peripheral analgesic (Anonymous, 2009). The metabolism of β-myrcene was studied in the rabbit and in the rat and has been shown to induce liver monooxygenases. The acute toxicity of β-myrcene was reported to be low and this monoterpene was shown to have no genotoxic and no teratogenic activity (Paumgartten et al., 1998).
CONCLUSION
It was concluded that Echinophora orientalis leaves was dominated with potent bioactive compounds. It was assumed that the oil might be exhibited various pharmacological and biological properties. Further experiments are needed to confirm the hypothesis.