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 high-performance 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 mass spectra indicate the presence of limonoid glucosides without the necessity of isolating the individual compounds. Two major limonoid glucosides – obacunone glucoside (OG) and nomilin glucoside (NG) – were identified in the methanol extract of the peel. The two limonoid glucosides were taken as the target and isolated by means of preparative HPLC on a C18 reversed-phase column with an acidic acetonitrile–water mobile phase. The structures of OG and NG were further confirmed by nuclear magnetic resonance spectrometry.