Chemical composition of the essential oil of Salvia grossheimii from Iran

Abstract

Fifty eight species of the genus Salvia (Lamiaceae) are found in Iran, 17 of which are endemic [1]. Due to the use of this genus or their essential oils in the food and drug industries [2], we are investigating the oils of Salvia spp. which grow wild or are cultivated in Iran. In this paper, we describe the analysis of the essential oil of S. grossheimii Sosn. which grows wild in many regions of Iran especially in Azarbayejan province. A literature search did not reveal any reference to previous work on the essential oil of this species. The aerial parts of Salvia grossheimii were collected from Azarbayejan province-koh Mishodagh. Essential oil isolated by hydrodistillation from the aerial parts was obtained in yields of 0.4% (w/w).The essential oil yields of other species in Iran were: S. nemorosa, 0.12% [3], S. reuterana, 0.15% [3], S. virgata, 0.48% [4], S. syriaca, 0.3% [4], S. atropatana, 0.1% [5], S. multicaulis, 0.2% [6], S. sahandica, 0.46% [7], S. spinosa 0.1% [8], S. limbata 0.07% [9], and S. mirzayanii, 2.2% [10]. A total of thirty-four compounds were characterized representing about 99.4% of the total components detected in S. grossheimii. The compounds identified with their percentages are given in Table 1. Based on the analysis of essential oil, the components were classified in three groups as follows: monoterpenes, sesquiterpenes, and esters. The oil was characterized by a high content of sesquiterpenes, which composed 88.8% of the oil. The main components were germacrene D (45.4%), -caryophyllene (22.4%), and bicyclogermacrene (7.1%). The identification of the compounds in the essential oil of different species of this genus in Iran shows that the major components of S. nemorosa, S. virgata, S. atropatana, and S. multicaulis is -caryophyllene [3–6]. Germacrene B and germacrene D are the main components in S. syriaca [4], while (E)--ocimene, -gurjunene, and germacrene D are the major constituents in S. reuterana [4]. (E)--ocimene, -caryophyllene, and isopentyl isovalerate are the major constituents in S. spinosa [8], while germacrene D, linalyl acetate, and linalool are the main components in S. limbata [9]. Twelve monoterpenes were identified in the essential oil of S. grossheimii, with contents ranging from 0.04 to 3.5% in the oil analyzed. Besides the mono- and sesquiterpenes, one ester, bornyl acetate (0.1%), was identified in the oil too. Plant Material and Isolation Procedure. Aerial parts of the plant (250 g) were collected during flowering in May 2006 from Azarbayejan province (Koh-Mishodagh) in Iran. A voucher specimen has been deposited in the Herbarium of the Research Institute of Forest and Rangelands (TARI). The essential oil was obtained by hydrodistillation of air-dried aerial parts in a clevenger-type apparatus for 3 h. The sample oil which was light yellow in color and was dried over anhydrous sodium sulfate and stored under nitrogen in a sealed vial until required. Gas Chromatography-Mass Spectrometry. GC and GC-MS analyses were performed using a Shimadzu GC-9A gas chromatograph and Varian 3400 GC-MS system equipped with a DB-5 fused silica column based on techniques published before [8, 9]. Identification of Components. The components of the oil were identified by comparison of their mass spectra to with those of a computer library or with authentic compounds and confirmed by comparison of their retention indices, either those of authentic compounds or data published in the literature [11].