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13C-NMR. Study on Isoalloxazine and Alloxazine Derivatives

✍ Scribed by Hans J. Grande; Robert Gast; Cees G. Van Schagen; Willem J. H. Van Berkel; Franz Müller

Book ID
102857839
Publisher
John Wiley and Sons
Year
1977
Tongue
German
Weight
715 KB
Volume
60
Category
Article
ISSN
0018-019X

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✦ Synopsis

Abstract

A series of isoalloxazine and alloxazine derivatives have been investigated by ^13^C‐NMR. The synthesis of selectively ^13^C‐enriched derivatives made it possible to assign unambiguously the signals due to the quaternary carbon atoms at position 4, 4a and 10a of the isoalloxazine ring system. The assignment of the other resonances was ensured by the use of selectively deuteriated and chemically modified compounds as well as by decoupling techniques. The assignments differ in part from those published by Breitmaier & Voelter [2] on FMN and FAD. The solvent dependence of the resonances has been studied in dioxan/water mixtures. The experimental data are compared with published MO calculations and discussed.

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