Phytopathological Chemistry of Black-rotten Sweet Potato

Part 16. Polyphenols in the Rotten Sweet Potato. (3)

Abstract

A polyphenol in the black-rotten sweet potato, A₂ component was separated and divided into two componets, A₂-a and A₂-b, by the countercurrent distribution. They were hydrolyzed with alkali to give caffeic acid and quinic acid, and supposed to be position isomers of chlorogenc acid. Among them, A₂-b was presumed to be identical with isochlorogenic acid that was isolated from coffee, beans by White and Barnes. It is supposed that A₂-a is contained in black-rotten sweet potato, and also transformed from the other component in the rotten sweet potato during the isolation treatment, such as heating, acidification, Pb-salt precipitation and its decomposition. A₁ component was found to have caffeic acid and quinic acid in it.
The authors wish to express their appreciation to Prof. Yusuke SUMIKI and Prof. Saburo FUNAHASHI for their guidances and advices.