Tannins and Related Compounds. CXIV. Structure of Novel Fermentation Products, Theogallinin, Theaflavonin and Desgalloyl Theaflavonin from Black Tea, and Changes of Tea Leaf Polyphenols during Fermentation

摘要: Continuing chemical examination of black tea has led to the isolation three novel fermentation products, theogallinin (1), theaflavonin (10) and desgalloyl (11). The structure 1 was established on basis physico-chemical evidence be a condensation product linked through pyrogallol-pyrogallol rings in theogallin (2) (-)-epigallocatechin 3-O-gallate (3), while 10 11 were characterized as B, B'-linked bisflavonoids formed by an oxidative coupling isomyricitrin (12) catechins [3 (4)]. Furthermore, high performance liquid chromatography analyses changes polyphenols during have revealed that original are more rapidly transformed endogenous phenol oxidase theasinensins (e.g.6, 8) oolongtheanin (13) than formerly known pigments, theafiavins.