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A predictive tool for assessing 13C NMR chemical shifts of flavonoids

✍ Scribed by Darcy C. Burns; David A. Ellis; Raymond E. March

Publisher
John Wiley and Sons
Year
2007
Tongue
English
Weight
222 KB
Volume
45
Category
Article
ISSN
0749-1581

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✦ Synopsis

Abstract

Herein are presented the ^1^H and ^13^C NMR data for seven monohydroxyflavones (3‐, 5‐, 6‐, 7‐, 2′‐, 3′‐, and 4′‐hydroxyflavone), five dihydroxyflavones (3,2′‐, 3,3′‐, 3,4′‐, 3,6‐, 2′,3′‐dihydroxyflavone), a trihydroxyflavone (apigenin; 5,7,4′‐trihydroxyflavone), a tetrahydroxyflavone (luteolin; 5,7,3′,4′‐tetrahydroxyflavone), and three glycosylated hydroxyflavones (orientin; luteolin‐6C‐β‐D‐glucoside, homoorientin; luteolin‐8C‐β‐D‐glucoside, vitexin; apigenin‐8C‐β‐D‐glucoside). When these NMR spectra are compared, it is possible to assess the impact of flavone modification and to elucidate detailed structural and electronic information for these flavonoids. A simple predictive tool for assigning flavonoid ^13^C chemical shifts, which is based on the cumulative differences between the monohydroxyflavones and flavone ^13^C chemical shifts, is demonstrated. The tool can be used to accurately predict ^13^C flavonoid chemical shifts and it is expected to be useful for rapid assessment of flavonoid ^13^C NMR spectra and for assigning substitution patterns in newly isolated flavonoids. Copyright © 2007 John Wiley & Sons, Ltd.

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