The Chemical Structure of Kaki-Tannin from Immature Fruit of the Persimmon (Diospyros Kaki L.).

Abstract

A partially purified tannin was prepared by a K2HPO4-precipitation method from immature persimmon fruit (Diospyros kaki L., cv. “Hiratanenashi,” astringent type). The kaki-tannin gave delphinidin and cyanidin on acid hydrolysis. Its methylated derivative showed Vmax 1720cm-1 in IR spectrum and had the molecular weight of ca. 1.38×104 daltons in MW. From the results of toluene-a-thiol treatment, it is suggested that the kaki-tannin consists of catechin, catechin-3-gallate, gallocatechin, gallocatechin-3-gallate and an unknown terminal residue, and belongs to proanthocyanidin B group with a carbon-carbon interfiavan linkage from C-4 of one unit to C-6 or C-8 of another unit. © 1978, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.