Chemical Compositions, Phytotoxicity, and Biological Activities of Acorus calamus Essential Oils from Nepal

Four essential oils from the leaf (P23) and rhizomes (P19, P22, P24) of Acorus calamus L., collected from various parts of Nepal, were obtained by hydrodistillation and analyzed by GC-MS. From a total of 61 peaks, 57 compounds were identified among the four essential oils accounting for 94.3%, 96.2%, 97.6%, and 94.1% of the oils, respectively. All of the essential oils were dominated by (Z)-asarone (78.1%-86.9%). The essential oils also contained (E)-asarone (1.9%-9.9%) and small amounts of gamma-asarone (2.0-2.3%), (Z)-methyl isoeugenol (1.5-2.0%), and linalool (0.2-4.3%). Allelopathic testing of the rhizome oil showed inhibition of seed germination of Lactuca sativa and Lolium perenne with IC50 values of 450 and 737 mu g/mL, respectively. The rhizome essential oil demonstrated stronger seedling growth inhibition of L. perenne than of L. sativa, however. The rhizome oil also showed notable brine shrimp lethality (LC50 = 9.48 mu g/mL), cytotoxic activity (92.2% kill on MCF-7 cells at 100 mu g/mL), and antifungal activity against Aspergillus niger (MIC = 19.5 mu g/mL).