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NMR assignment and characterization of proton exchange of the ellagitannin granatin B

✍ Scribed by Wayne E. Steinmetz

Publisher
John Wiley and Sons
Year
2010
Tongue
English
Weight
169 KB
Volume
48
Category
Article
ISSN
0749-1581

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✦ Synopsis

Abstract

Granatin B, a complex ellagitannin extracted from pomegranate fruit, has two equilibrating isomers, form a and form b. A full ensemble of proton and carbon‐13 NMR methods over a wide range of temperature enabled a complete assignment of the more abundant isomer and showed it to be form b. This result is based on the NMR data for granatin alone and agrees with the previous determinations which were based on a combination of chemical methods and a partial assignment of the NMR spectra. The new NMR spectra also yield exchange rates for the hydroxyl protons as a function of temperature. A molecular model involving hydrogen bonding provides an explanation for the exchange data. Copyright © 2010 John Wiley & Sons, Ltd.

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