Profiles of potentially antiallergic flavonoids in 27 kinds of health tea and green tea infusions.

摘要

Seven flavonoid profiles, some of which were reported to show antiallergic activity in vitro, were surveyed in 28 kinds of tea. Flavonoids were extracted with hot water, hydrolysed to aglycones and characterized by HPLC. Flavonols quercetin and kaempferol were found in 17 kinds of tea infusions, including Japanese green tea infusions. Myricetin was found in jasmine and pu-erh tea infusions. A flavone, luteolin, was found in 5 kinds of tea infusions including great plantain tea. Apigenin was found in 4 kinds of tea infusions including perilla leaf tea and scutellarein was found in 3 kinds of tea infusions. Scutellarein, which is a potent antiallergic and low cytotoxic flavonoid, was found in great plantain tea and was detected in perilla leaf and safflower tea infusions at concentrations of approximately 2 mg/g and 0.3 mg/g in dried whole tea leaves, respectively. The presence of scutellarein in both samples was confirmed by liquid chromatography/mass spectrometry.