Analysis of volatile constituents of Sideritis raeseri

The genus Sideritis L. was known in Ancient Greece already, mentioned by Theophrastus and Dioscurides. Popularly known as Ironwort, it is a traditional beverage in Balkan countries, one of the most used species is Sideritis raeseri Boiss. & Heldr., Lamiaceae (Sideritis raeseri herba). The EMA-HMPC is currently working on a Community Herbal Monograph. The aim of this study was to analyse the volatile compounds in Sideritis raeseri herba by SPME GC-MS. The plant material originated from Greece (Othrys Mountains). The harvests were carried out in June of 2011, 2012, and 2013, respectively, i.e. during the optimal phenophase of blooming. We identified 10 components in Sideritis raeseri herba (2011), that is 88.2% of the volatile components. The components identified in highest percentage were: γ-elemene (26.5%), β-caryophyllene (15.8%), and spathulenol (10.8%). Nine components were identified in the 2012 herb, that is 94.2% of the volatile components. These volatile components were identified in highest percentage: γ-elemene (32.3%), β-caryophyllene (14.9%) and spathulenol (9.7%). The analysis of the 2013 herb showed the presence of 10 components, and these represent 91,4% of the volatile components, and the volatile compounds present in highest percentage were: γ-elemene (29.5%), β-caryophyllene (15.4%) and spathulenol (10.1%). Further materials analysed included the Aetheroleum (2013), obtained by hydrodistillation, that showed the presence of 7 components that make up to 98.5% of volatiles. The main volatile compounds differed significantly in comparison to the herbal samples, the highest percentage showed: carvacrol (77.1%), nuciferol (8.2%), and α-bisabolol (6.6%). The aqua aromatica (2013), a side product of hydrodistillation, showed the presence of 4 components, i.e. 62.8% volatiles were identified. Essential oil compounds identified in highest percentage include: nuciferol (45.2%), spathulenol (11.6%) and caryophyllene oxide (5.6%).