Phytochemical studies on the extract and essential oils of Artemisia dracunculus L. (Tarragon)

Artemisia dracunculus L. (Tarragon) is a species of flowering plant within the family Asteraceae, commonly used as a dietary seasoning. During the present study, the plant was collected from Indian Institute of Integrative Medicines (IIIM Srinagar). Air dried shoots (room temperature 25-35C) were used to extract essential oil using Clevenger type apparatus for 3 h and analyzed. Thirty-four (34) compounds were identified using gas chromatographyflame ionization detector (GC-FID) and Gas chromatographymass spectrometry (GC-MS) analysis. Major constituents of the essential oil were trans-Anethole (28.06%), Z-β-ocimene (15.79%), Terpenolene (10.12%), Elemecin (10.08%), 1, 8 cineole (7.71%) and copaene (2.78%), etc. Comparing our results with those of other Artemisia species already published in the literature revealed considerable qualitative and quantitative similarity of the major constituents of the essential oils. As trans-Anethole is the major constituent, this chemo type may be useful for industrial exploitation as well as chemotaxonomic characterization.


INTRODUCTION
Artemisia is a genus of small herbs or shrubs widely distributed throughout the world but found mostly in Northern temperate regions. It belongs to the important family compositae (Asteraceae), which comprises about 1000 genera and over 20,000 species. Within this family, Artemisia is included into the tribe Anthemideae and comprises over 500 species. The 500 species of Artemisia are mainly found in Asia, Europe and North America. This genus is industrially important due to its insecticidal, antifungal, antibacterial, allelopathic and other properties. The genus is useful in Ayurveda, Homeopathy, Unani, Siddha and Western medicinal system (Ved and Goraya, 2008).
Chemical composition and biological activities of Artemisia spp. essential oils has been reported recently (Lopes-Lutz et al., 2008). Artemisia dracunculus L. (commonly known as Tarragon) finds an important place in the genus Artemisia and remains a subject of interest due to great variability in traditional medicinal use, plant morphology, reproductive behaviour, essential oil con-tent, composition, etc. Tarragon is a perennial, erect, herb or small shrub, widely distributed in India, China, Japan, North America, European countries, etc., between altitudes of 3000-4000 msl (Hooker, 1882 Tarragon is safe to use as dietary supplements or in functional foods . Biological characteristics and useful properties of tarragon are reported in a review recently (Aglarova et al., 2008). The dried aerial parts of A. dracunculus are used orally to treat epilepsy in Iranian traditional medicine (Khorasani, 1992).The species is also useful as sleep aid to mild sedative properties (Chevallier, 1996). It is reported that monoterpenes present in essential oil of A. dracunculus are responsible for anticonvulsant and sedative effect (Sayyah et al., 2004). Antidiabetic property is also supported recently by ethanolic extract (Ribnicky et al., 2004). Reports are available on chemical composition of A. dracunculus from different parts of the world (Pino, 1996;Irena and Krystyna, 1996;Pappas and Sturtz, 2001;Sayyah et al., 2004). The aim of the present study was to determine the chemical profile of essential oil of A. dracunculus L. by using different spectroscopic procedures like GC and GC-MS.

Plant material
The Himalaya is a well known source of variety of Medicinal and aromatic plants. The plant material of A. dracunculus was collected from various geographical regions like Sonmarg, Gulmarg, Gurez and was then transfered to IIIM germplasm and Field station Bonera, Pulwama. The plant material was then taken from IIIM germplasm for the extraction and isolation purposes.

Extraction of essential oil
The shade dried leaves and stem of the plant were finely chopped and then subjected to hydro distillation separately in a Clevenger like apparatus at 60C for 3 h. The oil obtained was dried over anhydrous sodium sulphate and stored at 4C in a sealed vial until analysis.

Essential oil analysis
GC/FID was carried out on Perkin Elmer auto system XL Gas Chromatograph 8500 series equipped with flame ionization detector (FID) and head space analyzer using a fused silica capillary RTX-1 Column (30 m x 0.25 mm, film thickness 0.25 mm) coated with dimethyl polysiloxane (RT × 1). Oven temperature was programmed from 60 to 290C with injector temperature of 230C and detector temperature of 250C. Injection volume was 1 μl, and nitrogen was used as a carrier gas (1.0 ml/min). GC-MS analysis was carried on a varian gas chromatograph series 3800 fitted with a VF 5 ms fused silica capillary column (30 m x 0.25 mm, film thickness 0.25 mm) coupled with a 4000 series mass detector under the following conditions: injection volume of 0.5 ml with split ratio 1:60, helium as carrier gas at 1.0 ml/min constant flow mode, injector temperature of 230C, oven temperature of 60 to 280C at 3C /min. Mass spectra was electron impact (EI+) mode,70 eV and ion source temperature was 250C. Mass spectra were recorded over 50-500 a.m.u range. Identification of the essential oil constituents was done on the basis of Retention Index [RI, determined with respect to homologous series of n-alkanes (C9-C24), Polyscience Corp., Niles IL] under the same experimental conditions), and co-injection with standards (Sigma Aldrich and standard isolates), MS Library search (NIST 98 and WILEY), by comparing with the MS literature data (Jennings and Shibamoto, 1980;Adams, 2007).