Tannins and Related Compouns. XXXVI. : Isolation and Structures of Theaflagallins, New Red Pigments from Black Tea

Abstract

A chemical examination of black tea polyphenols had led to the isolation of three new red pigments, spitheaflagallin 3-O-gallate (1), epitheaflagallin (2) and theaflagallin (3), together with the known theaflavins 4-7. The structures of the theaflagallins 1-3 have been determined on the basis of spectroscopic and chemical data as unusual benzotropolones formed by oxidative condensation of gallic acid and so-called gallocatechins.