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13C NMR spectroscopy of the withanolides and other highly oxygenated C28 steroids

✍ Scribed by Hugo E. Gottlied; I. Kirson

Publisher
John Wiley and Sons
Year
1981
Tongue
English
Weight
580 KB
Volume
16
Category
Article
ISSN
0749-1581

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✦ Synopsis

Abstract

The ^13^C NMR spectra of 29 highly oxygenated C, steroids with the withanolide skeleton, 24 of which are naturally occurring substances or acetates thereof, were recorded and the carbon signals fully assigned. The shifts of the heavily functionalized A/B ring system can serve as a ‘fingerprint’ for the different substitution patterns. A study of the effects of hydroxyl substitution in the ring D/side chain part of the molecules leads to conformational information, including preferred rotamers around the 17—20 and 20—22 bonds. Systems with both 17α‐ and 17β‐oriented side chains are thus analysed.

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