Thin-layer chromatographic separations of unsaponifiable components in seed oil of wild and cultivated sesame

This study was conducted to obtain basic informations on the unsaponifiable components in sesame seed. Four major lignan, sesamin, sesamolin, sesamol and sesangolin were analyzed to provide fine separation of unsaponifiable component fractions of seed oil in four wild and three cultivated sesame varieties by thin layer chromatography (TLC). The mean content of unsaponifiable components extracted from cultivated sesame oil was 2.4% (ranged 2.2 to 2.7), while that of wild ones showed 3.3% (ranged 2.3 to 4.0). The mean content of unsaponifiable components of wild species was higher than that of cultivated ones. Silicagel plates and chloroform/diethyl ether (9 : 1, v/v) as mobile phase on the first and second directions were utilized in TLC analysis. In one-dimensional TLC separation, sesamin, sesamolin, sesamol, sesangolin and tocopherol were identified as spots at the Rf values of 0.66, 0.76, 0.52, 0.66 and 0.88, respecitively. Sesamin and sesangolin were appeared at same spots with Rf value of 0.66. In two-dimensional TLC separation, sesamin and sesangolin showed different TLC pattern. This two-dimensional system could be adopted to provide pure fractions in preparative experiments for sesamin and sesangolin measurements of seed oil. Some other minor spots were also observed in S. alatum and S. radiatum showing void of sesamolin but containing sesangolin.