Characterization of Flavonol Conjugates in Immature Leaves of Pak Choi [Brassica rapa L. Ssp. chinensis L. (Hanelt.)] by HPLC-DAD and LC-MS/MS
- 1 June 2006
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of Agricultural and Food Chemistry
- Vol. 54 (13), 4855-4860
- https://doi.org/10.1021/jf060154j
Abstract
The flavonoid composition of immature leaves of pak choi [Brassica rapa L. ssp. chinensis L. (Hanelt.)] was investigated. Flavonol aglycone content was measured in 11 pak choi varieties, indicating significant differences (P < 0.05) in content between varieties and relatively high contents of kaempferol and isorhamnetin. Levels of quercetin ranged from 3.2 to 6.1 mg/100 g of dry weight (DW), whereas levels of isorhamnetin and kaempferol were significantly higher (8.1−35.1 and 36.0−102.6 mg/100 g of DW, respectively). A large number of glycoside and hydroxycinnamic acid derivatives of quercetin, kaempferol, and isorhamnetin were identified in cv. ‘Shanghai' by LC/UV-DAD/ESI-MS/MS. The UV-DAD data allowed identification of hydroxycinnamic acid derivatives, but detailed MS/MS fragmentations were required for the structure elucidation. Pak choi could be a potentially important source of dietary flavonols, in particular, kaempferol and isorhamnetin. Keywords: Food analysis; pak choi; flavonol; glycosides; hydroxycinnamic acid esters; liquid chromatography, mass spectrometryKeywords
This publication has 7 references indexed in Scilit:
- Characterisation of flavonols in broccoli (Brassica oleracea L. var. italica) by liquid chromatography–UV diode-array detection–electrospray ionisation mass spectrometryJournal of Chromatography A, 2004
- Characterization of the interglycosidic linkage in di‐, tri‐, tetra‐ and pentaglycosylated flavonoids and differentiation of positional isomers by liquid chromatography/electrospray ionization tandem mass spectrometryJournal of Mass Spectrometry, 2004
- Mass spectrometry in the structural analysis of flavonoidsJournal of Mass Spectrometry, 2004
- Cardiovascular Effects of Isorhamnetin and Quercetin in Isolated Rat and Porcine Vascular Smooth Muscle and Isolated Rat AtriaPlanta Medica, 2002
- Structure characterization of flavonoid O‐diglycosides by positive and negative nano‐electrospray ionization ion trap mass spectrometryJournal of Mass Spectrometry, 2001
- Hydroxycinnamic acid esters from broccoli floretsPhytochemistry, 1997
- Analysis of the Major Flavonol Glycosides Present in Four Varieties of Onion (Allium cepa) and Changes in Composition Resulting from AutolysisJournal of the Science of Food and Agriculture, 1997