Variation in Essential Oil Composition and Chiral Monoterpenes ofAchillea millefoliums.l. from Kaliningrad

Five clones of the Achillea millefolium-“complex” from different sites at Kaliningrad were cultivated in the Botanical Garden of Würzburg to investigate the oil composition of the flowerheads. The oil was obtained by steam distillation and the headspace method. Gas chromatography with an M.C.S.S. system (moving-capillary-stream-switching) was used to analyze chiral monoterpenes. The variability of the major components was examined by GC. The essential oils of five samples were characterized by sesquiterpenes with high chamazulene content whereas in one clone, azulenes were only detected in traces. The latter Achillea sample also differed in the monoterpene content. The oil contained mainly sabinene and less β-pinene as compared with the other clones. Despite the remarkable variation of monoterpenes, the distribution of chiral compounds remained constant. It was neither influenced by the ontogeny of the Achillea clones nor by the isolation method (distillation or headspace). Achillea plants with high chamazulene content were characterized by 85% up to 97% of the (+)-form of sabinene, whereas specimens with small concentration of chamazulene contained more than 90% of the (−)-form of sabinene. Due to the remarkable variation in phenotype and content pattern of the oil, the possible enantiospecific composition of monoterpenes of different yarrow species might serve as an additional chemical marker in Achillea taxonomy.