Browsing by Author "Valente, C"
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- Bioactive diterpenoids, a new jatrophane and two ent-abietanes, and other constituents from Euphorbia pubescensPublication . Valente, C; Pedro, M; Duarte, A; Nascimento, MSJ; Abreu, PM; Ferreira, MJUA new jatrophane diterpene, pubescenol (1), known ent-abietane lactones, helioscopinolide A (2) and B (3), and taraxerone, 24-methylenecycloartanol, and vanillin have been isolated from Euphorbia pubescens. Diterpenes 1-3 and previously described pubescene D (4) were shown to be moderate inhibitors of the growth of MCF-7, NCI-H460, and SF-268 human tumor cell lines, whereas compounds 2 and 3 also exhibited significant antibacterial activity against Staphylococcus aureus.
- Compostos Terpénicos Isolados de Euphorbia segetalisPublication . Madureira, AM; Valente, C; Palma, AC; Ascenso, JR; Ferreira, MJU
- Euphopubescenol and euphopubescene, two new jatrophane polyesters, and lathyrane-type diterpenes from Euphorbia pubescensPublication . Valente, C; Pedro, M; Ascenso, JR; Abreu, PM; Nascimento, MSJ; Ferreira, MJUThe structures of euphopubescenol and euphopubescene, two new macrocyclic jatrophane diterpene polyesters, isolated from the whole dried plant of Euphorbia pubescens, were established as 5alpha,8alpha,15beta-triacetoxy-3alpha-benzoyloxy-4alpha-hydroxy-9,14-dioxo-13betaH-jatropha-6(17),11E-diene (1) and 3beta,7beta,8beta,9alpha,14alpha,15beta-hexa-acetoxy-2betaH-jatropha-5E,11E-diene (2) by 1D- and 2D-NMR (COSY, HMQC, HMBC and NOESY), IR, EI-MS and EI-FTICR-MS. Two known lathyrane derivatives, jolkinol A (3) and jolkinol A (4), whose C-13-NMR spectra were assigned, were also isolated. Compounds 1-3 have been evaluated for their ability to inhibit the in vitro growth of three human tumour cell lines representing different tumour types, MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and SF-268 (CNS cancer). They inhibited both MCF-7 and NCI-H460 cell lines, with GI(50) values ranging between 40.9 muM and 95.3 muM, but were found to be ineffective as growth inhibitors of the SF-268 cell line.
- Pubescenes, jatrophane diterpenes, from Euphorbia pubescens, with multidrug resistance reversing activity on mouse lymphoma cellsPublication . Valente, C; Ferreira, MJU; Abreu, PM; Gyemant, N; Ugocsai, K; Hohmann, J; Molnar, JThe macrocyclic jatrophane diterpene polyesters, pubescenes A-D (1-4) were isolated from the whole dried plant of Euphorbia pubescens, and evaluated for multidrug resistance (MDR) reversing activity on mouse lymphoma cells. All the compounds displayed very strong activity compared with the positive control verapamil. Pubescene D (4) is a new compound, whose structure was established as 3beta9alpha,-diacetoxy-7beta-benzoyloxy-15beta-hydroxy-14-oxo-2betaH-jatropha-5E,12E-diene by spectroscopic methods, including H-1-H-1 COSY, HMQC, HMBC and NOESY.
- Study of the secondary metabolites of the methanol extract of Euforbia pubescens. Evaluation of their antibacterial activityPublication . Valente, C; Duarte, A; Ascenso, JR; Abreu, PM; Ferreira, MJU
- Three new jatrophane-type diterpenes from Euphorbia pubescensPublication . Valente, C; Ferreira, MJU; Abreu, PM; Pedro, M; Cerqueira, F; Nascimento, MSJThree new macrocyclic jatrophane diterpene polyesters, named pubescenes A (1), B (2), and C (3), and the known compounds indole-3-aldehyde and scopoletin have been isolated and characterised from the whole dried plant of Euphorbia pubescens. The structures of the new compounds were established by spectroscopic means including 2D-NMR techniques such as COSY, HMQC, HMBC and NOESY experiments. Compounds 1-3 were evaluated for their in vitro effect on the growth of three human cancer cell lines MCF-7 (breast), NCI-H460 (lung) and SF-268 (CNS) as well as for their capacity to interfere with the proliferation of human peripheral blood lymphocytes. They exhibited a moderate growth inhibitory effect on the cancer cell line NCI-H460. No effect was observed on the mitogenic response of human lymphocytes to PHA.