Tannins and Related Compounds. XXXVI.1) Isolation and Structures of Theaflagallins, New Red Pigments from Black Tea

Abstract

A chemical examination of black tea polyphenols has led to the isolation of three new red pigments, epitheaflagallin 3-0-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. © 1986, The Pharmaceutical Society of Japan. All rights reserved.