Lc-Ms/Ms Profiling and Characterization of Active Components from Medicinal Gingers (Curcuma Xanthorrhiza and Zingiber Zerumbet)
Ruslay, Sharin (2006) Lc-Ms/Ms Profiling and Characterization of Active Components from Medicinal Gingers (Curcuma Xanthorrhiza and Zingiber Zerumbet). Masters thesis, Universiti Putra Malaysia.
Ground fresh rhizomes of Zingiber zerumbet and Curcuma xanthorrhiza were exhaustively extracted using acetone, ethanol and water. Acetone extract of Z. zerumbet and ethanol extract of C. xanthorrhiza gave highest yield of crude extract. The crude extracts were fractionated between water and hexane, ethyl acetate and butanol. All the crude extracts and fractions were screened for antioxidant activity. Ethyl acetate and butanol fractions exhibited good antioxidant activity, of which ethyl acetate fractions from both plants showed strongest antioxidant activity. High Performance Liquid Chromatography (HPLC) profiling was done to analyse the peak patterns of extracts and fractions of both plants. Liquid chromatography- UV diode-array and electrospray ionization mass spectroscopy (ESI-MS) have been used to characterize the active fractions of Z. zerumbet and C. xanthorrhiza. The active fraction (ethyl acetate) from Z. zerumbet was analysed to afford kaempferol-3-O-rhamnoside (A) and its isomeric acetyl derivative as kaempferol-3-O-(2” or 3”-O-acetyl)rhamnoside (B), kaempferol-3-O-(4”-O-acetyl)rhamnoside (C), kaempferol-3-O-(3”,4”-O-diacetyl)rhamnoside (D) and kaempferol-3-O-(2”,4”-O-diacetyl)rhamnoside (E). All the structures were confirmed by using various spectroscopic method including HPLC (spiking method), ESI-MS, IR, UV and NMR spectroscopy. Three components, bisdemethoxycurcumin (F), demethoxycurcumin (G) and curcumin (H) were identified from active ethyl acetate fraction of C. xanthorrhiza. The LC-DAD-MS/MS profiling of Z. zerumbet and C. xanthorrhiza have been developed for the first time as per our knowledge. Phytochemical studies on the rhizomes of Z. zerumbet have yielded 7 pure compounds. Hexane fraction afforded zerumbone (1), while ethyl acetate fraction gave demethoxycurcumin (9), kaempferol (11), kaempferol-3-O-rhamnoside (15) or (A), kaempferol-3-O- (4”-O-acetyl)rhamnoside (14) or (C), kaempferol-3-O- (3”, 4”-O-diacetyl)rhamnoside (6) or (D) and kaempferol-3-O- (2”, 4”-O-diacetyl)rhamnoside (18) or (E).
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