The lipid and volatile oil of the seed and aerial parts of Onopordum alexandrinum Boiss. growing in Egypt and their antioxidant activity

Purpose The study of the lipid of the seed and aerial parts of Onopordum alexandrinum Boiss., family Asteraceae, growing in Egypt led to the isolation and identification of the unsaponifiable and fatty acid fractions of both the seed and the aerial parts of the plant. Also, isolation of volatile oil of the seed and studying their antioxidant activity. Subjects and methods The constituents of the unsaponifiable fraction of the seed, aerial parts of the plant and volatile oil of the seeds were identified by Gas liquid chromatography (GLC) analysis. The radical scavenging effects of the tested extracts of both the seed and the aerial parts of the plant using DPPH free radicals. Results GLC analysis of the unsaponifiable fraction of the seeds indicated a mixture of hydrocarbons ranging from C 13 to C 28 ; cholesterol, campasterol, stigmasterol, and β-sitosterol were also present. GLC analysis of the fatty acid methyl esters of the seeds indicated the presence of eight fatty acids. Also, GLC analysis of the unsaponifiable fraction of the aerial parts of the plant indicated a mixture of hydrocarbons ranging from C 17 to C 28 . Cholesterol, campasterol, stigmasterol, and β-sitosterol were also present. GLC analysis of the fatty acid methyl esters of the aerial parts indicated the presence of nine fatty acids. Sixteen compounds were identified by GLC analysis represented 77.97% of the total composition of the oil of the seeds. Conclusion The unsaponifiable fractions of both the seed and the aerial parts of the plant and volatile oil showed a strong antioxidant activity, whereas the fatty acid fractions showed a moderate antioxidant activity.