Original contributions 68 Z Arznei- Gewurzpla | 21 (2): 68–72 | ERLING Verlag GmbH & Co. KG | 2016 Introduction Sideritis pisidica Boiss. & Heldr. (known as mountain tea) is consumed as an herbal tea which has been used to treat various ailments such as com- mon cold in folk medicine since anci- ent times in Anatolia. Located in the west of Lake Beysehir, Dedegöl Moun- tains, a part of the Taurus Mountains stretching from the southeast Anatolia to Aegean Sea, harbor countless ende- mic plant species. One of these ende- mic plant species found abundantly in this region is Sideritis pisidica Boiss. & Heldr. which is appreciated very much for its unique taste and refreshing aro- ma. The plant is a member of Sideritis genus in the Labiatea family. Sideri- tis genus comprises over 150 species which spreads from Bahamas to China and from Germany to Morocco (1,2). Most species, however, are mainly dis- tributed in Mediterranean region whe- re Turkey and Spain have the highest number of Sideritis species (2). Turkey alone possess 46 Sideritis species pri- marily in Marmara and Aegean regions (2,3). Sideritis species contains a various phytochemical substances including terpenes, flavonoids, essential oil, iridoids, coumarins, lignanes, and sterols (2). Most common substances almost found in very Sideritis species are diterpenes, flavonoids and essen- tial oils all of which possess pharma- cological activities (4–6). Head Space Gas Chromatography Mass Spectrometry (HS-GC/MS) is presently a broadly-used tool for the identifying of the composition of plant volatile fraction, thanks to its simple and rapid management (7). To our knowledge, there are no literatures identifying vo- latile composition of Sideritis pisidica Boiss. & Heldr. by using HS-GS/MS, or an extensive analysis of volatile com- pounds in general. In the present stu- dy, we separated the aerial parts into stem, leaf and blossom by expecting that each of the plant part contains dif- ferent volumes of volatile compounds. Materials and methods Plant materials Sideritis pisidica Boiss. & Heldr. samples were collected from Dedegöl Mountains of the Konya Provenience in Turkey (37° 37' 52.6" N and 31° 22' 55.3" E with an elevation of 1762.23 m) located in the west of Lake Beysehir and the northwest of Yesildag town. The plants were harvested at a stage when a resin-like substance secreted on all aerial parts, indicating the right time for the harvest of the plant used for speciically herbal tea. The aerial parts of the plant materials were air- dried at the temperature of approxi- mately 23 °C at the shade for one week. The plant materials were then bunched and keep at the room temperature with avoiding light exposure until the onset of the analyses. The plant material was identiied by Prof. Dr. Lüti Behçet (Fac- ulty of Science and Literature of Bingol University). A voucher specimen (No. BIN 3321; Collector No. ME01) was deposited at the Herbarium of Fac- ulty of Science and Literature of Bingol University, Turkey. Stems, leaves and blossoms of the sage samples were separated before grinding into ine powder using an Ultra Centrifugal Mill (Retsch ZM 200; Haan, Germany). Ap- proximately one g of powder from each plant part was placed in 10-mL glass vials stoppered with a silicon-teflon septum. HS-GC/MS analysis The isolation, quantiication and identi- ication of headspace volatile contents were carried out on a GC equipped with a mass spectrometry detector (Agilent M. Ergun, N. Ergun and N. Ozbay Analysis of volatile constituents of Sideritis pisidica Boiss. & Heldr. by head space gas chromatography mass spectrometry (HS-GC/MS) Abstract Sideritis pisidica Boiss. & Heldr. plants are usually collected on their natural stands and used an herbal tea in Turkey, which leads to a higher demand for the plant more than ever. Naturally grown Sideritis pisidica Boiss. & Heldr. plants were collected from Dedegöl Mountains in Ana- tolia. Aerial parts (stems, leaves and blossoms) of the plants were analyzed by Head Space Gas Chromatography Mass Spectrometry HS-GC/MS to identify volatile compounds. In total 38, 36 and 34 compounds were identiied in the stem, leaf and blossom, having a total area of 92.07, 95.17 and 97.59%, respectively. The main volatile components present in great quantity in the stem were α-pinene (26.15%), sabinene (15.06%) and b-caryophyllene (9.99%); in the leaf α-pinene (32.95%), sabinene (15.43%), b-pinene (6.66%) and b-caryophyllene (6.12%); and in the blossom α-pinene (41.65%), sabinene (27.10%) and sabinene hydrate (5.11%). The study clearly revealed that aromatic volatile components in the stem, leaf or blossom of the Sideritis pisidica Boiss. & Heldr. difer from each other. Keywords Dedegöl Mountains, HS-GC/MS, Mountain tea, sabinene, α-pinene, b-caryophyllene