GC-MS Analysis of the Essential Oil from Seseli mairei H. Wolff (Apiaceae) Roots and Their Nematicidal Activity

The essential oil (EO) was extracted from aerial parts with insecticidal and fungicidal activity. Herein, the hydro-distilled essential oils of Seseli mairei H. Wolff roots were determined by GC-MS. A total of 37 components were identified, (E)-beta-caryophyllene (10.49%), β-geranylgeranyl (6.64%), (E)-2-decenal (6.17%) and germacrene-D (4.28%). The essential oil of Seseli mairei H. Wolff had nematicidal toxicity against Bursaphelenchus xylophilus with a LC₅₀ value of 53.45 μg/mL. The subsequent bioassay-guided investigation led to the isolation of three active constituents: falcarinol, (E)-2-decenal, and octanoic acid. The falcarinol demonstrated the strongest toxicity against B. Xylophilus (LC₅₀ = 8.52 μg/mL). The octanoic acid and (E)-2-decenal also exhibited moderate toxicity against B. xylophilus (LC₅₀ = 65.56 and 176.34 μg/mL, respectively). The LC₅₀ of falcarinol for the toxicity of B. xylophilus was 7.7 and 21 times than that of octanoic acid and (E)-2-decenal, respectively. Our findings demonstrate that the essential oil from Seseli mairei H. Wolff roots and their isolates may be developed as a promising natural nematicide.