Seasonal Variation in Essential oil Composition of Artemisianilagirica var. septentrionalis from Foot Hills of Western Himalaya

Essential oils composition of the aerial parts of Artemisia nilagirica (Clarke) Pamp. var. septentrionalis Pamp. in different seasons viz. spring, summer, rainy, autumn and winter seasons under foot hills agroclimatic conditions of western Himalaya were analyzed and compared by GC–FID and GC–MS. Essential oils were mainly composed of monoterpenoids (59.0%-77.3%) and sesquiterpenoids (15.7%-31.6%). The major constituents identified were artemisia ketone (38.3%-61.2%), chrysanthenone (1.5%-7.7%), germacrene D (3.1%-6.8%), β-caryophyllene (1.9%-6.8%), germacra-4,5,10-trien-1-α-ol (1.9%-4.9%) and artemisia alcohol (1.4%-3.6%). Compositional analysis showed significant variations in the terpenoid compositions due to seasonal variations. Further, this is for the first time the seasonal variations in essential oil compositions of artemisia ketone rich chemotype of A. nilagirica var. septentrionalis is being reported from India.