Limonoid Glucosides in Seeds of Shiikuwasha (Citrus depressa HAYATA)

Limonoid glucosides extracted from seeds of Shiikuwasha (Citrus depressa HAYATA) grown in Okinawa were separated by column chromatography and high-performance liquid chromatography (HPLC), and then analyzed by thin layer chromatography, HPLC and nuclear magnetic resonance spectrometry. The 17-β-D-glucopyranoside derivatives of nomilin, limonin, deacetylnomilin and nomilinic acid were identified. The seeds contained 1.27 g of total limonoid glucosides per 100 g on a dry weight basis, showing two-fold higher levels than that found in other common citrus seeds.