Please use this identifier to cite or link to this item: https://doi.org/10.1016/j.chroma.2004.07.032
Title: An improved method for the analysis of major antioxidants of Hibiscus esculentus Linn
Authors: Shui, G. 
Peng, L.L. 
Keywords: Antioxidants
Flavonoids
Lady's finger
Solid phase extraction
Issue Date: 3-Sep-2004
Citation: Shui, G., Peng, L.L. (2004-09-03). An improved method for the analysis of major antioxidants of Hibiscus esculentus Linn. Journal of Chromatography A 1048 (1) : 17-24. ScholarBank@NUS Repository. https://doi.org/10.1016/j.chroma.2004.07.032
Abstract: Major antioxidants of aqueous ethanol extract from Lady's Finger (Hibiscus esculentus Linn) were systematically investigated in this study. Firstly, high-performance liquid chromatography (HPLC) was applied to identify antioxidant peaks in a sample by spiking the sample extract with 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical, which was prepared from manganese dioxide and ABTS. Secondly, in order to identify the elution period of major antioxidant peaks, the antioxidant capacities of different fractions from solid-phase extraction (SPE) were measured, and the chromatograms of fractions were also recorded. Lastly, multiple mass spectrometry (MS n) was used to elucidate the possible chemical structures of antioxidants, and nuclear magnetic resonance (NMR) was further applied for structure confirmation. The major antioxidant compounds in lady's finger were identified to be quercetin derivatives and (-)-epigallocatechin using HPLC-MS and HPLC-MS n (n = 2-4) techniques. It was found that about 70% of total antioxidant activity was contributed by four quercetin derivatives. The structures of major antioxidants, which were isolated by semi-preparative RP-HPLC with two tandem C 18 columns, were further confirmed using UV-vis absorption spectroscopy and 13C NMR spectra. Quercetin 3-O-xylosyl (1‴ → 2″) glucoside, quercetin 3-O-glucosyl (1‴ → 6″) glucoside, quercetin 3-O-glucoside and quercetin 3-O-(6″-O-malonyl)-glucoside were first identified and characterized as major antioxidants in lady's finger. © 2004 Elsevier B.V. All rights reserved.
Source Title: Journal of Chromatography A
URI: http://scholarbank.nus.edu.sg/handle/10635/113356
ISSN: 00219673
DOI: 10.1016/j.chroma.2004.07.032
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

SCOPUSTM   
Citations

61
checked on Sep 12, 2019

WEB OF SCIENCETM
Citations

52
checked on Sep 12, 2019

Page view(s)

71
checked on Sep 6, 2019

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.