Chemical Constituents of the Essential Oil of Galium mite var. roseum ghahramaninejad from Iran

Abstract

The genus Galium belongs to the family Rubiaceae. Some species of the genus have been reported to possess antispasmodic, diuretic, and vulnerary effects [1]. Plants of this genus are used for fermenting milk to cheese, and, due to this utility, the plant has been named Shir-panir in Iranian culture. The aerial parts of Galium species are also added to different types of food as herb or spice to improve the flavor. Galium mite var. roseum ghahramaninejad is distributed in Turkey, Iraq, Transcaucasus, and Iran. G. mite Boiss. & Hohen. and G. subvelutinum ssp. mite (Boiss. & Hohen.) Ehrend are the other names for the plant [2]. The chemical constituents of the essential oil of G. hercynicum, G. humifusum, G. salicifolium, and G. verum as members of the Galium species have been investigated before [3–5]. In the present work, the chemical composition of the essential oil of G. mite var. roseum ghahramaninejad is reported for the first time. To our knowledge, no previous phytochemical study has been performed on the essential oil of G. mite var. roseum ghahramaninejad. The plant material was collected in August 2012 from the Dena region of Iran and identified at the Department of Phytochemistry, University of Yasouj (Iran). Voucher specimens were deposited at the Herbarium of the Yasouj University, Yasouj, Iran (No. HYU25517). The aerial parts were air-dried at ambient temperature in the shade and hydrodistilled using a Clevenger-type apparatus for 4 h. The essential oil was obtained from the aerial parts of G. mite var. roseum ghahramaninejad as a yellow liquid in 0.1% (w/w) yield. The essential oil was analyzed by GC-MS (60–240 C at 3 C/min rate) in an Agilent Technology 7890A GC coupled to a 5975C-MS instrument using an HP-5MS capillary column (phenyl methyl siloxane, 30 m 0.25 mm; 0.25 m film thickness). The injector temperature was 240 C; injection was in the split mode (1:50). Helium was used as carrier gas at a flow rate of 0.9 mL/min. MS spectra were obtained using electron impact at 70 eV with a scan interval of 0.5 s and mass range from 35 to 550 m/z. The GC/MS analysis of the essential oil resulted in 38 compounds, making up 87.4% of the total composition. The most abundant constituent of the oil was borneol (18.0%), followed by aliphatic aldehydes, including n-nonanal (7.5%), (2E)-undecanal (7.0%), and (2E,4E)-decadienal (6.1%). According to Table 1, the volatile oil contained 12 aldehydes (42.1%), eight oxygenated monoterpenes (26.6%), five ketones (8.6%), three oxygenated sesquiterpenes (3.5%), six alkanes (2.2%), and three sesquiterpenes (1.8%). Unlike other reported species of Galium genus, the essential oil of G. mite var. roseum ghahramaninejad contained significant amounts of aliphatic aldehydes.