Background: In general, seasonal growing of plants influences chemical composition and biological activities of essential oils. Objectives: 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.
Materials and Methods:The oil was extracted by hydro-distillation from two samples collected in different seasons, and analyzed by GC-FID and GC-MS. Results: 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%). Conclusions: Based on these observations, wide variation is detected in the chemical composition of the oil obtained from the same plant in different seasons.