Chemical composition and antioxidant activity of Sium sisarum essential oils

Nat. Volatiles & Essent. Oils, 2017; 4(1): 29-32 Öztürk et al. RESEARCH ARTICLE Chemical composition and antioxidant activity of Sium sisarum essential oils Gözde Öztürk1, Betül Demirci1,*, Ahmet Duran2, Fahim Altınordu2, K. Hüsnü Can Başer3 Department of Pharmacognosy, Faculty of Pharmacy, Anadolu University, 26470, Eskisehir, TURKEY. Department of Biology, Faculty of Science, Selçuk University, 42075, Konya, TURKEY. 3 Department of Pharmacognosy, Faculty of Pharmacy, Near East University, 99138, Nicosia, CYPRUS. 1 2 *Corresponding author. Email: Abstract The genus Sium (Apiaceae) is presented by perennials with fibrous roots, inflorescence paniculate-corymbose, white petals, minute sepals, slightly lateral compressed fruits in the Flora of Turkey. The essential oils of the fruits and aerial parts of Sium sisarum L. collected from two different localities Kavak and Ladik in Samsun, Turkey, were obtained by hydrodistillation. The essential oils were assigened as EO1 (fruit, Kavak), EO2 (aerial parts, Kavak), EO3 (fruit, Ladik), EO4 (aerial parts, Ladik). All samples were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS), simultaneously. γ-Terpinene (71.8, 64.2, 42.3, 39.0 %) and p-cymene (16.4, 23.4, 33.8, 33.0 %) were found as major constituents of the analysed samples, respectively. β-Pinene (7.7 %) and limonene (8.3 %) were identified as the major components for EO3. Also, β-pinene (4.0 %), limonene (10.0 %) and ar-curcumene (2.0 %) were found as the major components for EO4. Additionally, the quantitative in vitro testing using DPPH was conducted to determine the antioxidant capacity. UV absorbance of the samples were measured at 517 nm using a microplate spectrophotometer system. According to the assay results, antioxidant potential of the tested essential oils was comparatively weak (IC 50 > 30 mg/mL). Keywords: Sium sisarum, gas chromatography, gas chromatography-mass spectrometry, DPPH antioxidant activity Introduction The genus Sium (Apiaceae) is describe as perennials with fibrous roots; petioles not persistent, leaves 1pinnate with broad leaflets, inflorescence paniculate-corymbose, bracts and bracteoles present, sepals minute, petals white, fruit slightly compressed laterally; mericarps narrowly elliptic-oblong; dorsal and lateral ridges shortly elevated-spongiose; dorsal vittae three per vallecula, commissural six, in Flora of Turkey (Davis et al, 1972). S. sisarum is known as Skirret grows in Cyprus, Eastern Europe, Russia, Iran; Adana, Kars, Hakkari, Karabük and Samsun provinces in Turkey (Bakış et al., 2011). The roots of S. sisarum are very sweet and can be eaten raw or cooked. Skirret makes a great addition to soups, where its soft texture will cause it to break apart and act as a sweetener and thickener (Harvey, 1984). Materials and Methods Plant material The Sium sisarum materials were collected in 2014 and 2015 from two different localities Kavak (A.Duran 10517 & M.Çelik) and Ladik (A.Duran 9987 & F.Altınordu) in Samsun province, Turkey. The fruits and aerial parts of S. sisarum were hydrodistillated for 3 h using Clevenger-type apparatus. The essential oils were coded as EO1 (fruit, Kavak), EO2 (aerial parts, Kavak), EO3 (fruit, Ladik), EO4 (aerial parts, Ladik). The essential oil yields were calculated as 2.0, 0.2, 1.3, and 0.2%, v/w, respectively. 29 Nat. Volatiles & Essent. Oils, 2017; 4(1): 29-32 Öztürk et al. Gas chromatography - flame ionization detection (GC-FID) analysis The essential oils were analyzed by GC using a Hewlett Packard 6890 system (SEM Ltd, Istanbul, Turkey) and an HP Innowax fused silica capillary column (FSC) (60 m x 0.25 mm ∅, with 0.25 µm film thickness) was used with nitrogen at 1 mL/min. Initial oven temperature was 60 °C for 10 min, and increased at 4 °C/min to 220°C, then kept constant at 220 °C for 10 min and increased at 1 °C/min to 240 °C. Injector temperature was set at 250 °C. Percentage compositions of the individual components were obtained from electronic integration using flame ionization detection (FID, 250 °C) (Demirci, et al., 2008). Relative percentages of the separated compounds were calculated from FID chromatograms as cited in Table 1. Gas chromatography - mass spectrometry (GC-MS) analysis GC-MS analysis was performed with a Hewlett-Packard GCD, system (SEM Ltd, Istanbul, Turkey) and Innowax FSC column (60 m x 0.25 mm, 0.25 µm film thickness) was used with Helium. GC oven temperature conditions were as described above, split flow was adjusted at 50 mL/min, the injector temperature was at 250 °C. Mass spectra were recorded at 70 eV. Mass range was from m/z 35 to 425 as previously reported (Demirci, et al., 2008). Identification of components Identification of the essential oil components were carried out by comparison of their relative retentiontimes with those of authentic samples or by comparison of their relative retention index (RRI) to series of n-alkanes. Computer matching against commercial (Wiley GC-MS Library, MassFinder Software 4.0) (McLafferty & Stauffer, 1989, Hochmuth, 2008), and in-house “Başer Library of Essential Oil Constituents” built up by genuine compounds and components of known oils, as well as MS literature data (Joulain & König, 1998) was used for the identification as also previously reported in detail (Demirci, et al., 2008). 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity Serial dilutions were carried out with stock solutions (10 mg/mL) of the essential oils to obtain the concentrations of 10, 5, 25×10-1, 125×10-2, 625×10-3, 3125×10-4 mg/mL. Diluted solutions were mixed with DPPH (Sigma Aldrich, USA) and allowed to stand for 30 min for any reaction to occur. The UV absorbance was recorded at 517 nm at room temperature using a microplate spectrophotometer. The experiment was performed three times and average absorption was noted for each concentration. Ascorbic acid was used as a positive control. The percentage of inhibition was calculated using equation. The IC50 value, which is the concentration of the test materials that inhibits 50% of the free radical concentration, was calculated as mg/mL (Kumarasamy et al., 2007).  (Abs control - Abs sample )   x100 Abs control  Percentage Inhibition =  Results and Discussion The essential oils obtained by hydrodistillation from fruit and aerial parts of S. sisarum was analyzed by GCFID and GC-MS. γ-terpinene (71.8, 64.2, 42.3, 39.0 %) and p-cymene (16.4, 23.4, 33.8, 33 %) were found as major constituents of all samples. β-pinene (7.7 %) and limonene (8.3 %) were identified as a major constituents for EO3. Also, β-pinene (4.0 %), limonene (10.0 %) and ar-curcumene (2.0 %) were found as a major constituents for EO4. Other constituents were given in Table 1. 30 Nat. Volatiles & Essent. Oils, 2017; 4(1): 29-32 Öztürk et al. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was used to determine the antioxidant capacity of S. sisarum. However, (...truncated)