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