On the tea tannins in green tea. Isolation of tea tannin II in crystalline state

Abstract

On the paper chromatogram of crude tea tannin, fannin, four spots are to be seen, RF values of which being 0.81, 1.72, 1.67 and 0.52, these excepting 0.72, correspond to tea tannin Itea tannin Itea catechin I tea catechin II, which have been formerly separated by the present author (see Plate 1). The author has recently isolated tea tannin II, the RE value of which is corresponding (see Plate II). The crystalline form of this tea tannin II is shown in Plate III, m. p. 248∼9°, [α]18D=-173°. Its aqueous solution has a hard astringent taste, when heated with dilute separates gallic acid and is converted into a reddish brown substance. The absorption spectra of these four substances are shown in Plate III. From above the newly isolated substance in recognizable as l-gallocatechin gallate. © 1955, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.