Document Type

Article

Publication Title

ARKIVOC

Department

Chemistry

ISSN

1551-7012

Volume

2014

Issue

5

DOI

10.3998/ark.5550190.p008.583

First Page

1

Last Page

29

Publication Date

1-1-2014

Abstract

The NMR-structures of six polyphenols, resveratrol (1), (-)-epicatechin (2), pelargonidin chloride (3), cyanidin chloride (4), cyanin chloride (5), and keracyanin chloride (6), were fully assigned. For the glycosylated polyphenols 5 and 6, the three-dimensional solution structure and long-range 1 H- 13C-coupling constants across the glycosidic bond were measured. Satisfactory fit to standard Karplus-equations was achieved for glycosides directly attached to the aromatic core in cyanin chloride. Molecular dynamics simulation data in vacuum at the AM1-level of theory were shown to approximate the NMR-solution data reasonably well. Selective HCl-catalyzed H/D-exchange was observed for aromatic protons H6 and H8 in flavonoid structures containing a 5,7-metadisubstituted chromelynium core with free OH-groups. The exchange took place readily in compounds 3, 4, and 6, whereas 1, 2, and 5 did not exchange.

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Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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