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NMR study of quinolizidine alkaloids: relative configurations, conformations

✍ Scribed by Phuong Mai Le; Marie-Thérèse Martin; Nguyen Van Hung; Daniel Guénard; Thierry Sévenet; Nicole Platzer

Publisher
John Wiley and Sons
Year
2005
Tongue
English
Weight
892 KB
Volume
43
Category
Article
ISSN
0749-1581

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✦ Synopsis

Abstract

Extracts of fruits and leaves of Connarus paniculatus afford six quinolizidine alkaloids which were identified as piptanthine, 18‐epipiptanthine, ormosanine, homoormosanine, podopetaline (monohydrochloride) and homopodopetaline on the basis of high‐field NMR studies. 1D and 2D NMR experiments provide complete assignments of the ^1^H and ^13^C spectra. In conjunction with detection of nuclear Overhauser effects (NOESY), these results allow detailed structure characterization including determination of relative configurations for the chiral sites and conformational analysis. Exchange phenomena involving nitrogen inversion were detected. Copyright © 2005 John Wiley & Sons, Ltd.

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