Variability of the essential oil content and composition among the wild populations of Achillea biebersteinii Afan. from Iran: occurrence of new nepetalactones chemotypes

In this study, the chemical composition of essential oils from twenty-three wild populations of Achillea biebersteinii Afan., growing wild in different parts of Iran, were determined by means of gas chromatography (GC) and GC-mass spectrometry (GC-MS) analyses. Based on the dry weight of samples, the oil content of studied populations varied from 0.44% (Nenor) to 1.62% (Golool) with an average value of 0.81%. In total, twenty-five compounds were identified in the essential oil of all samples corresponding about 92.5-99.1% of the chemical composition. All essential oils were characterized by a high amount of monoterpenoid compounds (99.1-99.2%), especially oxygenated ones (48.5-90%), which were almost dominant in all cases and with a trace amount of sesquiterpenes (0-0.3%). 1,8-Cineole (6.5-68.3%) was generally found as the principal component of most essential oils, followed by p-cymene (1.4-38.6%). The noticeable point of present study was the occurrence of nepetalactones chemotypes in plants of the Nepeta species. These compounds were detected in the essential oils of fourteen of twenty-three populations, which were mostly at least one of the three major components (4.3-43.3%) too.