Atividade anti-tripanosomicida de triterpenes pentacíclicos isolados de Austroplenckia populnea (Celastraceae)

Four pentacyclic triterpenes isolated from Austroplenckia populnea and four compounds of known anti T. cruzi or anti-malarial activity were tested. Of those triterpenes tested 20alpha-hydroxy-tingenone showed high activity, epikatonic acid was less active, while populnilic and populninic acids were inactive against the trypanosome of the subgenus Schizotrypanum tested. Benzonidazole, nifurtimox, ketoconazole and primaquine presented a remarkable dose-dependent inhibitory effect reaching practically to a total growth inhibition of the parasite at the end of incubation time. The trypanosome tested appear to be a suitable model for preliminary screen for anti T. (S.) cruzi compounds.Foram testados quatro triterpenos pentacíclicos isolados de Austroplenckia populnea e quatro compostos de conhecida atividade anti-T. cruzi ou anti-malárica. Dos triterpenos testados 20alfa-hidroxi-tingenona mostrou atividade elevada, ácido epicatônico foi menos ativo, enquanto ácido populnílico e populnínico foram inativos contra o tripanossoma do subgênero Schizotrypanum testado. Benzonidazole, nifurtimox, cetoconazole e primaquina apresentaram efeito inibitório dose-dependente atingindo praticamente a inibição total do crescimento do parasita no final do tempo de incubação. O tripanossoma testado mostrou ser um modelo adequado para uma seleção preliminar de compostos anti. T. (S.) cruzi

Triterpene esters isolated from leaves of Maytenus salicifolia Reissek.

The triterpene ester (3b)-olean-18-en-3-yl stearate (1), together with (3b)-urs-12-en-3-yl stearate (2), and (3b)-lup-20(29)-en-3-yl stearate (3) were isolated from leaves of Maytenus salicifolia Reissek (Celastraceae). The structure of 1, a new compound, including its configuration, was established by 1H, 13C, and DEPT-135 NMR data, including 2D experiments( HSQC, HMBC, COSY, and NOESY). The molecular mass (692 Da) was confirmed by gas chromatography coupled with mass spectrometry (CG/ MS)

Two epimeric friedelane triterpenes isolated from Maytenus truncata Reiss : 1H and 13C chemical shift assignments.

An NMR study of 3˛- and 3ˇ-friedelinol is described. In addition to conventional 1D NMR methods, 2D shift-correlated NMR experiments HMQC [(1J(C,H)], HMBC [nJ(C,H); n D 2 and 3] and 2D 1H,1H-NOESY were used for 1H and 13C chemical shift assignments of these triterpenes

Total assignment of 1H and 13C NMR spectra of two 3,4-secofriedelanes from Austroplenckia populnea.

Two new 3,4-secofriedelanes, 3,4-seco-28-hydroxyfriedelan-3-oic acid (1) and 3,4-secofriedelan-3-oic acid (2),were isolated from the leaves of Austroplenckia populnea (Celastraceae).The structureswere established by 2D NMR spectroscopic techniques (COSY, HMQC, HMBC and NOESY)

Constituintes químicos e atividade antiespermatogênica em folhas de Austroplenckia populnea (Celastraceae)

Folhas de Austroplenckia populnea (mangabarana, marmelinho do campo) foram submetidos a estudo fitoquímico. do extrato hexânico foram isolados e identificados três triterpenos pentacíclicos e um sesquiterpeno agarofurânico inédito. Realizou-se testes de atividade antiespermatogência utilizando parte deste extrato. Os resultados mostraram uma redução significativa do número de espermatozóides no epidídimo

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 CDCl3 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 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

Salicassin, an unprecedented chalcone diterpene adduct and a quinone methide triterpenoid from Maytenus salicifolia.

In continuation of our work on Maytenus salicifolia, we report herein the isolation and structuralelucidation of two new compounds, salicassin (1), a diterpene-chalcone adduct with an unprecedented C-framework, and (16b)-16-hydroxypristimerin (2), a quinone methide triterpenoid. Their structures wereelucidated on the basis of spectroscopic analysis, including 1D- and 2D-NMR techniques (COSY,ROESY, HSQC, and HMBC). In addition, 22 known compounds were isolated and characterized bycomparison of their spectra with reported data. Compound 2, structurally related to the well knowncytotoxic quinone methide triterpenoids, exhibited an antiproliferative effect on HeLa, A-549, and HL-60 human cell lines, with IC50values of 2.2, 3.2, and 2.7 mm, respectively

Antigiardial activity of the hexane extract of Maytenus gonoclada mart.

Plants of the Maytenus genus have been used in folk medicine in Brazil for treatment of gastrointestinal motility disturbances such as diarrhea. The present study was performed to evaluate antigiardial activity of the hexane extract and triterpenes isolated from the branches of Maytenus gonoclada Mart. (Celastraceae). The hexane extract and triterpenes were examined for antigiardial activity using the colorimetric method against Giardia lamblia (ATCC 30888). The hexane extract exhibited antigiardial activity. This result may partly explain and support the use of plants of the Maytenus genus for the treatment of diarrhea in folk medicine in Brazil

A pentacyclic triterpene from Maytenus imbricata: structure elucidation by X-ray crystallography

A pentacyclic triterpene, 3β,30-dihydroxy-lup-20(29)-ene, was isolated from the powder extract of Maytenus imbricata. The structure and stereochemistry of the compound were established by spectroscopic techniques and unambiguously determined by single crystal X-ray crystallography. The crystal structure shows one molecule in the asymmetric unit. The crystal packing is stabilized by O–H···O intermolecular hydrogen bonds, which give rise to infinite helical chains along the c unit cell axis. The intra-molecular geometry was analyzed using MOGUL, a knowledge base of molecular geometry derived from the Cambridge Structural Database (CSD)