Massive Accumulation of Gallic Acid and Unique Occurrence of Myricetin, Quercetin, and Kaempferol in Preparing Old Oolong Tea
Citations Over TimeTop 15% of 2008 papers
Abstract
Old oolong tea, tasting superior and empirically considered beneficial for human health, is prepared by long-term storage accompanied with periodic drying for refinement. Analyzing infusions of three old and one newly prepared oolong teas showed that significant lower (-)-epigallocatechin gallate (EGCG) but higher gallic acid contents were detected in the old teas compared to the new one. The possibility of releasing gallic acid from EGCG in old tea preparation was supported by an in vitro observation of gallic acid degraded from EGCG under heating conditions mimicking the drying process. Moreover, three minor flavonols, myricetin, quercetin, and kaempferol, that were undetectable in the new tea occurred in all of the three old teas. Converting the new oolong tea into an old one by periodic drying revealed the same characteristic observation, i.e., massive accumulation of gallic acid presumably released from EGCG and unique occurrence of flavonols putatively decomposed from flavonol glycosides.
Related Papers
- → A Comparative HPLC Analysis of Myricetin, Quercetin and Kaempferol Flavonoids Isolated From Gambian and Indian Moringa oleifera Leaves(2018)21 cited
- → [Retracted] Two Myricetin‐Derived Flavonols from Morella rubra Leaves as Potent α‐Glucosidase Inhibitors and Structure‐Activity Relationship Study by Computational Chemistry(2022)13 cited
- → Potential interactions among myricetin and dietary flavonols through the inhibition of human UDP-glucuronosyltransferase in vitro(2022)12 cited
- → The Vasodilating Effect and Angiotensin Converting Enzyme Inhibition Activity of Three Dietary Flavonols: Comparsion between Myricetin, Quercetin and Morin, <i>in vitro</i>(2019)9 cited
- → Anti-proliferative and total ERK1/2 inhibitory effects of plant flavonols on Human cervical cancer (HeLa) cells(2018)5 cited