Carbon-13 NMR spectra of some pentacyclic triterpenoids with the olean-12-ene and 18α-olean-12-ene skeleton
✍ Scribed by Giuliana Severini Ricca; Bruno Danieli; Giovanni Palmisano; Helmut Duddeck; M. Hani A. Elgamal
- Publisher
- John Wiley and Sons
- Year
- 1978
- Tongue
- English
- Weight
- 339 KB
- Volume
- 11
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
The 13C NMR spectra of some pentacyclic triterpenoids, 3~-acetoxy-ll-oxo-olean-12-ene-30-oic acid methyl ester, 3~-acetoxy-ll-oxo-olean-12-ene-29-oic acid methyl ester, the corresponding 11-desoxo methyl esters, 3~-acetoxy-ll-oxo-18cw-olean-l2-en-30-oic acid methyl ester and 3~-acetoxy-ll-oxo-18~-olean-12en-29-oic acid methyl ester are discussed. The shielding data are interpreted in term of the different orientation of the carbomethoxy group and of the change in configuration at the D/E ring junction and are diagnostically valuable for the difierentiation of the mentioned compounds.
A full assignment of the 13C NMR signals of a large number tural urs-12-ene el~cidation,'-~ of skeleton triterpenes as has well having been as for an performed biogenetic olean-12-ene for struc-and