Chemical composition and allelopathic, antibacterial, antifungal and in vitro acetylcholinesterase inhibitory activities of yarrow (Achillea millefolium L.) native to India

The present study was conducted to evaluate the variability in the essential oil yield and chemical composition of Achillea millefolium L. (whole aerial-parts, leaves and inflorescence) grown in the subtropical region of north India during annual growth. The allelopathic, antibacterial, antifungal, and antiacetylcholinesterase activities of the oil were also examined. The essential oil yield varied due to harvesting stages and plant-parts processed (0.10-0.70%). The oils obtained from different stages and plant -parts were analysed using GC-FID and GC-MS. Altogether thirty-nine constituents, forming 93.0-97.8% of the total oil composition were identified. Major constituents of the oils were germacrene D (1.1-46.6%), sabinene (4.0-38.9%), borneol (4.7-24.9%), camphor (0.6-17.6%), alpha-pinene (0.8-11.7%), artemisia ketone (3.1-12.9%), chamazulene (0.8-9.6%), y-cadinene (0.3-8.2%), and camphene (0.2-5.7%). Cluster analysis grouped overall compositions into six main groups based on their dominant components. It was observed that season of harvesting and plant -parts affect the essential oil yield and chemical composition of A. millefolitan. The chemical composition of the examined essential oil was different from those described from other geographical origins. Moreover, this oil displayed a significant allelopathic activity.