Flavones in Green Tea

Part I. Isolation and Structures of Flavones Occurring in Green Tea Infusion

Abstract

Nineteen flavones were newly found in green tea infusion. Four pigments were isolated, and one of them was identified as vitexin (C-glycosyl flavone). As the remained pigments were obtained only in small quantities, their properties were studied spectrophotometrically. Similarity of their UV spectra and color reactions suggested that all of them have the same skeleton as 5, 7, 4'-trihydroxyfiavone (apigenin). The major one has high water solubility and deep greenish yellow color in aqueous solution, so that it may be the important constituents related to the color of green tea infusion.