Next Article in Journal
Next Article in Special Issue
Previous Article in Journal
Previous Article in Special Issue
Molecules 2009, 14(2), 598-607; doi:10.3390/molecules14020598
Communication

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

1,* , 2, 1, 1, 3 and 4
Received: 20 November 2008; in revised form: 10 January 2009 / Accepted: 21 January 2009 / Published: 4 February 2009
(This article belongs to the Special Issue Triterpenes and Triterpenoids)
Download PDF [90 KB, uploaded 18 June 2014]
Abstract: Friedelin (1), 3b-friedelinol (2), 28-hydroxyfriedelin (3), 16a-hydroxyfriedelin (4), 30-hydroxyfriedelin (5) and 16a,28-dihydroxyfriedelin (6) were isolated through fractionation of the hexane extract obtained from branches of Salacia elliptica. After a week in CDCl3 solution, 16a-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 CDCl3 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 13C-NMR and 2D NMR spectral data are reported for compounds 4 and 7.
Keywords: Salacia elliptica; Celastraceae; 16α-Hydroxyfriedelin; 3-Oxo-16-methylfriedel-16-ene Salacia elliptica; Celastraceae; 16α-Hydroxyfriedelin; 3-Oxo-16-methylfriedel-16-ene
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Export to BibTeX |
EndNote


MDPI and ACS Style

Duarte, L.P.; Silva de Miranda, R.R.; Rodrigues, S.B.V.R.; De Fátima Silva, G.D.; Filho, S.A.V.; Knupp, V.F. Stereochemistry of 16a-Hydroxyfriedelin and 3-Oxo-16-methylfriedel-16-ene Established by 2D NMR Spectroscopy. Molecules 2009, 14, 598-607.

AMA Style

Duarte LP, Silva de Miranda RR, Rodrigues SBVR, De Fátima Silva GD, Filho SAV, Knupp VF. Stereochemistry of 16a-Hydroxyfriedelin and 3-Oxo-16-methylfriedel-16-ene Established by 2D NMR Spectroscopy. Molecules. 2009; 14(2):598-607.

Chicago/Turabian Style

Duarte, Lucienir Pains; Silva de Miranda, Roqueline Rodrigues; Rodrigues, Salomão Bento Vasconcelos Rodrigues; De Fátima Silva, Grácia Divina; Filho, Sidney Augusto Vieira; Knupp, Vagner Fernandes. 2009. "Stereochemistry of 16a-Hydroxyfriedelin and 3-Oxo-16-methylfriedel-16-ene Established by 2D NMR Spectroscopy." Molecules 14, no. 2: 598-607.



Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert