Tannins and Related Compounds. CXVIII. Structures, Preparation, High-Performance Liquid Chromatography and Some Reactions of Dehydroellagitannin-Acetone Condensates

Abstract

The dehydroellagitannins having a dehydrohexahydroxydiphenoyl ester group in the molecule were found to undergo highly regio- and stereospecific condensation with acetone in the presence of ammonium ion under almost neutral conditions. This reaction was successfully applied to high-performance liquid chromatographic analysis to detect the dehydroellagitannins in the plant extract. Furthermore, the reactions of the acetone condensates with L-cysteine methyl ester were examined, and appear to be applicable to structural studies of dehydroellagitannins.