Screening for limonoid glucosides in Citrus tangerina (Tanaka) Tseng by high-performance liquid chromatography-electrospray ionization mass spectrometry

A screening method for limonoid glucosides in the peel of Citrus tangerina (Tanaka) Tseng, which utilizes highperformance liquid chromatography (HPLC) with diode-array detection and interfaced to electrospray ionization mass spectrometry, has been developed. In this way, the UV-Vis spectra and the m ass spectra indicate the presence of limonoid glucosides without the necess ity of isolating the individual compounds. Two major limonoid glucosides - obacunone glucoside (OG) and nomilin glucoside (NG) - were identified in th e methanol extract of the peel. The two limonoid glucosides were taken as t he target and isolated by means of preparative HPLC on a C-18 reversed-phas e column with an acidic acetonitrile-water mobile phase. The structures of OG and NG were further confirmed by nuclear magnetic resonance spectrometry . (C) 2000 Elsevier Science B.V. All rights reserved.