The Seasonal Variations of the Chemical Composition of Essential Oil Obtained From Scrophularia frigida

In general, seasonal growing of plants influences chemical composition and biological activities of essential oils. Therefore, the aerial parts of Scrophularia frigida (S. frigida) were used in the current study to find seasonal variations in the content and composition of essential oil. The oil was extracted by hydro-distillation from two samples collected in different seasons, and analyzed by GC-FID and GC-MS. In total, 18 and 20 components were identified and quantified in the oil of summer and autumn samples representing 97.42% and 94.77% of the oil components, respectively. The essential oil of autumn sample was mainly composed of fatty acid derivatives (42.69%). The major components of the autumn oil were palmitic acid (30.49%), phytol (12.99%), L-linalool (11.41%), and hexahydrofarnesyl acetone (6.65%). The essential oil of summer sample was dominated by oxygenated monoterpenes (68.91%), L-linalool (38.69%), geraniol (11.20%), α-terpineol (9.99%), and palmitic acid (7.32%). Based on these observations, wide variation is detected in the chemical composition of the oil obtained from the same plant in different seasons.