Stereochemistry of 16α-Hydroxyfriedelin and 3-Oxo-16-methylfriedel-16-ene Established by 2D NMR Spectroscopy

Friedelin (1), 3β-friedelinol (2), 28-hydroxyfriedelin (3), 16α-hydroxyfriedelin (4), 30-hydroxyfriedelin (5) and 16α,28-dihydroxyfriedelin (6) were isolated through fractionation of the hexane extract obtained from branches of Salacia elliptica. After a week in CDCl(3) solution, 16α-hydroxyfriedeli...

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Detalles Bibliográficos
Autores principales: Duarte, Lucienir Pains, Silva de Miranda, Roqueline Rodrigues, Rodrigues, Salomão Bento Vasconcelos, de Fátima Silva, Grácia Divina, Filho, Sidney Augusto Vieira, Knupp, Vagner Fernandes
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Molecular Diversity Preservation International 2009
Materias:
Communication
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6253764/
https://www.ncbi.nlm.nih.gov/pubmed/19214150
http://dx.doi.org/10.3390/molecules14020598
Descripción
Sumario:Friedelin (1), 3β-friedelinol (2), 28-hydroxyfriedelin (3), 16α-hydroxyfriedelin (4), 30-hydroxyfriedelin (5) and 16α,28-dihydroxyfriedelin (6) were isolated through fractionation of the hexane extract obtained from branches of Salacia elliptica. After a week in CDCl(3) solution, 16α-hydroxyfriedelin (4) reacted turning into 3-oxo-16-methylfriedel-16-ene (7). This is the first report of a dehydration followed by a Nametkin rearrangement of a pentacyclic triterpene in CDCl(3) solution occurring in the NMR tube. These seven pentacyclic triterpenes was identified through NMR spectroscopy and the stereochemistry of compound 4 and 7 was established by 2D NMR (NOESY) spectroscopy and mass spectrometry (GC-MS). It is also the first time that all the (13)C-NMR and 2D NMR spectral data are reported for compounds 4 and 7.

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