Analysis of dietary phytosterols from Nelumbo Nucifera seeds of Korea

초록

The medicinal value of Nelumbo Nucifera (lotus) seeds has been known for centuries in Korea. However, few researchers have taken interest in phytosterols (plant sterols) in the lotus seeds. The purpose of this study was to investigate both the quality and quantity of sterols in the steryl esters and free sterols from ethanol extract of lotus seeds. The Siheung raw lotus seeds from Korea were extracted with ethanol and then extracted with hexane. This extract was subjected to silica gel column chromatography with hexane/diethyl ether (from 100:0, 90:1, -1:100) and ethyl acetate (100%) at last. The quality and quantity of sterols in the steryl esters and free sterols were determined by TLC, NMR, and GC-MS in the form of trimethysilyl ester derivative. The results showed that sterols of lotus seed oil occur mainly as esters of fatty acids and free sterols. The content of β-sitosterol was higher than other sterols in the steryl esters of lotus seed oil. Campesterol, β-sitosterol, and β-amyrin were main free sterol contents in the lotus seed oil and the content of β-sitosterol was significantly higher than others. Stigmasterol and isofucosterol were trace sterol contents in the lotus seed oil and identified using GC-MS.