Chemical Composition, Free-Radical-Scavenging and Insecticidal Properties, and General Toxicity of Volatile Oils Isolated from Various Parts of Echinophora orientalis

Abstract

The composition of the volatile oils from the seeds, shoots and roots of Echinophora orientalis Hedge & Lamond, a perennial aromatic herb of the family Apiaceae growing in Iran, was analyzed by GC-MS and GC-FID. Essential oil of this plant has been used as a natural preservative in dairy products industries. There were at least six compounds, α-pinene, myrcene, p-cymene, l-limonene, p-cymen-8-ol and 1,7- octadiene 3,6-dimethylene, common in seeds, shoots and roots volatile oils. While, m-tolualdehyde, cuminal, perillene and germacrene D were present both in seeds and shoots volatile oils, spathulenol was found in both seeds and roots volatile oils. Myristicin, terpenolene, α-phellandrene and 1,5,5-trimethyl-6-(3-methyl-buta-1,3- dienyl)-cyclohexene were identified in the volatile oils of shoots and roots of E. orientalis. The volatile oils of the seeds, unlike roots and shoots, had high percentage of sesquiterpenes. The roots and shoots volatile oils were found to be rich in monoterpenes. Oxygenated compounds were abundant in the volatile oils of the seeds and roots, but non-oxygenated hydrocarbons were the major of volatile components in the volatile oil of the shoots. The free-radical-scavenging activity of the oils was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. These volatile oils exhibited weak to moderate levels of free-radical-scavenging properties with 50 values of 3.87, 2.06 and 0.35 µg/mL for the seeds, shoots and roots, respectively. While the volatile oils displayed no insecticidal activity against Tribolium castaneum, noticeable general toxicity was displayed by all oils towards brine shrimp.