The sterols of Astragalus species from Iran: GLC separation and quantification

This paper presents the content and composition of free sterols in a number of Astragalus species from Iran. Free sterols of roots and seeds were analysed quantitatively and qualitatively by gas-liquid chromatography. Four major 3-beta-hydroxysterols (cholesterol, campesterol, stigmasterol and beta-sitosterol) were identified in roots of 18 species and in seeds of five species of Astragalus. beta-Sitosterol was the main free sterol in both roots and seeds. The cholesterol content in seeds was higher than that in roots. Trace amounts of cholesterol were detected in roots of only four species. beta-Sitosterol accounted for 34.4-69.2 and 76.8-81.8% of the total lipid content in roots and seeds, respectively. The beta-sitosterol content in roots and seeds of Astragalus species varied from 6.3 to 35.7 and 93.3 to 164.5mg/100g dry weight, respectively. Total free sterol content in seeds varied from 112.09 to 204.04mg/100g dry weight, significantly higher than those in roots (7.5 to 43.4mg/100g dry weight). The chemotaxonomic values of free sterols and total lipid profiles of some of the representative species are discussed.