The UVA and Aqueous Stability of Flavonoids Is Dependent on B-Ring Substitution
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- 作者：Sabia Maini ; Heather L. Hodgson ; Ed S. Krol
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2012
- 出版时间：July 18, 2012
- 年：2012
- 卷：60
- 期：28
- 页码：6966-6976
- 全文大小：575K
- 年卷期：v.60,no.28(July 18, 2012)
- ISSN：1520-5118
文摘
Flavonols such as kaempferol and quercetin are believed to provide protection against ultraviolet (UV)-induced damage to plants. Recent in vitro studies have examined the ability of flavonols to protect against UV-induced damage to mammalian cells. Stability of flavonols in cell culture media, however, has been problematic, especially for quercetin, one of the most widely studied flavonols. As part of our investigations into the potential for flavonols to protect skin against UV-induced damage, we have determined the stability of a series of flavonols that differ only in the number of substituents on the B-ring. We measured the stability of these flavonols over time to UVA radiation, Dulbecco鈥檚 modified Eagle鈥檚 medium (DMEM), and Dulbecco鈥檚 phosphate-buffered saline (DPBS) using high performance liquid chromatography with UV detection (HPLC鈥揢V). The identification of the breakdown products of flavonols was accomplished by using a hybrid quadrupole linear ion trap mass spectrometer coupled with liquid chromatography. Tandem mass spectrometric analysis (MS/MS) of flavonol photoproducts was confirmed by comparing with the known standard samples. We have determined that flavonol stability decreases with increasing B-ring substitution, suggesting that future investigation of potential photoprotective flavonols will need to be cognizant of this trend.