Acta Pharm. 51 (2001) 147-151

Seasonal variations in the content and composition of the essential oil of Micromeria thymifolia (Scop.) Fritsch

SANDA VLADIMIR-KNEZEVIC,^1* NIKOLA BLAZEVIC² and  ZDENKA KALOGJERA¹

¹Department of Pharmacognosy, Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia
²Irex-Aroma, Zagreb, Croatia

The yield of essential oil obtained by hydrodistillation from aerial parts of Micromeria thymifolia (Scop.) Fritsch varied from 0.3% to 0.5% (V/m) during vegetation period. The oils were characterised by a very high content of oxygenated monoterpenes (90.2-96.5%). Other components were monoterpene hydrocarbons and sesquiterpenes. Piperitenone oxide, pulegone and piperitone were identified as the major components of the investigated oils (GC, GC-MS). Significant seasonal variations in the relative amounts of the main components were confirmed. A continuous reduction in the oxide fraction with an accompanying increase in the proportion of ketones was observed.

Keywords: Micromeria thymifolia (Lamiaceae), essential oil, piperitenone oxide, pulegone, piperitone