Molecules 2012, 17(11), 13439-13456; doi:10.3390/molecules171113439
Article

New Triterpenes from Maytenus robusta: Structural Elucidation Based on NMR Experimental Data and Theoretical Calculations

1, 1,* email, 1, 1, 2, 1, 3 and 1
1 Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG, Brazil 2 Escola de Farmácia, Universidade Federal de Ouro Preto, 35400-000, Ouro Preto, MG, Brazil 3 Departamento de Química e Exatas, Universidade Estadual do Sudoeste da Bahia, 45206-191, Jequié, BA, Brazil
* Author to whom correspondence should be addressed.
Received: 12 September 2012; in revised form: 5 November 2012 / Accepted: 7 November 2012 / Published: 12 November 2012
(This article belongs to the Special Issue Triterpenes and Triterpenoids)
PDF Full-text Download PDF Full-Text [238 KB, Updated Version, uploaded 14 November 2012 11:29 CET]
The original version is still available [238 KB, uploaded 12 November 2012 13:03 CET]
Abstract: Leaves of Maytenus robusta (Celastraceae) were subjected to phytochemical investigation mainly directed at the isolation of pentacyclic triterpenes. The compounds friedelin (1), β-friedelinol (2), 3-oxo-21β-H-hop-22(29)-ene (7), 3,4-seco-friedelan-3,11β-olide (8), 3β-hydroxy-21β-H-hop-22(29)-ene (9), 3,4-seco-21β-H-hop-22(29)-en-3-oic acid (10), 3,4-seco-friedelan-3-oic acid (11), and sitosterol were identified in the hexane extract of M. robusta leaves. Compounds 8 and 9 are described herein for the first time. The structure and stereochemistry of both compounds were experimentally established by IR, HRLC-MS, and 1D (1H, 13C, and DEPT 135) and 2D (HSQC, HMBC and COSY) NMR data and supported by correlations with carbon chemical shifts calculated using the DFT method (BLYP/6-31G* level). Compounds 7 and 10 are also described for the first time, and their chemical structures were established by comparison with NMR data of similar structures described in the literature and correlations with BLYP/6-31G* calculated carbon chemical shifts. Compound 9, a mixture of 11 and sitosterol, and 3β,11β-dihydroxyfriedelane (4) were evaluated by the Ellman’s method and all these compounds showed acethylcholinesterase inhibitory properties.
Keywords: Maytenus robusta; pentacyclic triterpenes; NMR; DFT calculations; acetylcholinesterase inhibitory activity

Supplementary Files

Article Statistics

Load and display the download statistics.

Citations to this Article

Load and display citations from CrossRef.

Cite This Article

MDPI and ACS Style

Sousa, G.F.; Duarte, L.P.; Alcântara, A.F.C.; Silva, G.D.F.; Vieira-Filho, S.A.; Silva, R.R.; Oliveira, D.M.; Takahashi, J.A. New Triterpenes from Maytenus robusta: Structural Elucidation Based on NMR Experimental Data and Theoretical Calculations. Molecules 2012, 17, 13439-13456.

AMA Style

Sousa GF, Duarte LP, Alcântara AFC, Silva GDF, Vieira-Filho SA, Silva RR, Oliveira DM, Takahashi JA. New Triterpenes from Maytenus robusta: Structural Elucidation Based on NMR Experimental Data and Theoretical Calculations. Molecules. 2012; 17(11):13439-13456.

Chicago/Turabian Style

Sousa, Grasiely F.; Duarte, Lucienir P.; Alcântara, Antônio F.C.; Silva, Grácia D.F.; Vieira-Filho, Sidney A.; Silva, Roqueline R.; Oliveira, Djalma M.; Takahashi, Jacqueline A. 2012. "New Triterpenes from Maytenus robusta: Structural Elucidation Based on NMR Experimental Data and Theoretical Calculations." Molecules 17, no. 11: 13439-13456.

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