Ellagitannins and Oligomeric Proanthocyanidins of ThreePolygonaceous Plants

June 7, 2021

Title

Ellagitannins and Oligomeric Proanthocyanidins of ThreePolygonaceous Plants

Author

Yun-Qiu Li

Year

2021

Journal

MDPI

Abstract

The aim of this study was to characterize hydrolyzable tannins in Polygonaceous plants, asonly a few plants have previously been reported to contain ellagitannins. FromPersicaria chinensis, anew hydrolyzable tannin called persicarianin was isolated and characterized to be 3-O-galloyl-4,6-(S)-dehydrohexahydroxydiphenoyl-D-glucose. Interestingly, acid hydrolysis of this compound affordedellagic acid, despite the absence of a hexahydroxydiphenoyl group. From the rhizome ofPolygonumruncinatumvar.sinense, a large amount of granatin A, along with minor ellagitannins, helioscpoininA, davicratinic acids B and C, and a new ellagitannin called polygonanin A, were isolated. Basedon 2D nuclear magnetic resonance (NMR) spectroscopic examination, the structure of polygonaninA was determined to be 1,6-(S)-hexahydroxydiphenoyl-2,4-hydroxychebuloyl-β-D-glucopyranose.These are the second and third hydrolyzable tannins isolated from Polygonaceous plants. In addition,oligomeric proanthocyanidins ofPersicaria capitatumandP. chinensiswere characterized by thioldegradation. These results suggested that some Polygonaceous plants are the source of hydrolyzabletannins not only proanthocyanidins

Instrument

V-560, FT/IR-410, J-725

Keywords

ellagitannin; hydrolyzable tannin; proanthocyanidin; Persicaria; Polygonum; Polygo-naceae