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1.
Polymers (Basel) ; 15(13)2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37447510

RESUMO

Untreated wastewater pollution causes environmental degradation, health issues, and ecosystem disruption. Geopolymers offer sustainable, eco-friendly alternatives to traditional cement-based materials for wastewater solidification and removal. In this study, we investigate how wastewater containing organic and inorganic pollutants can be removed using geopolymer mixes based on metakaolin incorporation with cement kiln dust as an eco-friendly material. The present investigation compares the efficacy of two different techniques (solidification and adsorption) for reducing dye contaminants and heavy metals from wastewater using a geopolymer based on metakaolin incorporation with cement kiln dust. This study investigated the adsorption capacity of a geopolymer based on metakaolin incorporating two different ratios (20% and 40% by weight) of cement kiln dust (MC1 and MC2) for the reactive black 5 dyeing bath effluent (RBD) only and in a combination of 1200 mg/L of Pb2+ and Cd2+, each separately, in aqueous solutions under different adsorption parameters. The results of the adsorption technique for the two prepared geopolymer mixes, MC1 and MC2, show that MC1 has a higher adsorption activity than MC2 toward the reactive black 5 dyeing bath effluent both alone and in combination with Pb2+ and Cd2+ ions separately. The study also looked at using MC1 mix to stabilize and solidify both the dyeing bath effluent alone and its combination with 1200 mg/L of each heavy metal individually inside the geopolymer matrix for different time intervals up to 60 days of water curing at room temperature. The geopolymer matrix formed during the process was analyzed using FTIR, SEM, and XRD techniques to examine the phases of hydration products formed. The results showed that MC1 effectively adsorbs, stabilizes, and solidifies the dying bath effluent for up to 60 days, even with high heavy metal concentrations. On the other hand, geopolymer mixes showed an increase in mechanical properties when hydration time was increased to 60 days. According to our findings, the type of geopolymer developed from metakaolin and 20 wt.% cement kiln dust has the potential to be employed in the treatment of wastewater because it has good adsorption and solidification activity for the reactive black 5 dye effluent alone and for a mixture of dye pollutants with both Pb2+ and Cd2+ ions separately. Our results have significant implications for wastewater treatment and environmental remediation efforts, as they offer a sustainable solution for managing hazardous waste materials.

2.
Int J Biol Macromol ; 184: 689-700, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34174304

RESUMO

In this investigation, a novel alginate complex was developed for the selective separation of molybdenum (Mo(VI)) ions from some rare earth elements (REEs). In this regard, alginate as a natural polysaccharide was impregnated and modified with 2-hydroxy-5-nonylacetophenone oxime (Lix-84) and characterized using FT-IR, TGA/DTA and SEM-EDX. The relation between medium acidity, adsorption kinetics, sorbent dose, isotherm models, temperature and Mo(VI) recovery was investigated. It was concluded that the impregnation stage promoted the Mo(VI) separation. The kinetics and isotherm data were well-fitted and matched with the pseudo-first-order model and Langmuir isotherm model; respectively. The Langmuir maximum adsorption capacity of Mo(VI) reached 72.2 mg/g. The developed material showed excellent separation performance towards Mo ions over the investigated REEs. The desorption and recovery of the loaded Mo(VI) ions were achieved using 1.0 M HCl. Reutilization of Alg/Lix-84 was confirmed up to three adsorption-desorption cycles with no damage of the beads as proved with SEM analysis. The adsorption mechanism of molybdenum onto Alg/Lix-84 was elucidated through FTIR and XPS measurements and was found to be governed by both electrostatic interaction and ion exchange. Therefore, the developed material has a promising potential for the selective separation of molybdenum from REEs-containing solution.


Assuntos
Alginatos/química , Metais Terras Raras/análise , Molibdênio/análise , Oximas/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Extração Líquido-Líquido , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
3.
J Ethnopharmacol ; 176: 27-34, 2015 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-26475120

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Olax mannii Oliv. (Olacaceae) is among the many medicinal plants used in Nigeria for the ethnomedicinal management of both cancer and inflammation. Such plants represent potential sources of innovative therapeutic agents for the treatment of cancer and other malignant disorders. While the majority of medicinal plants exert their anticancer effects by direct cytotoxicity on tumor cells, it is important that other mechanisms through which these plants can exhibit anticancer effects are investigated. Preliminary studies indicated that Olax mannii leaves are rich sources of novel flavonoid glycosides. The detailed chemistry as well the mechanisms through which these flavonoid constituents may exert their cancer chemo-preventive and therapeutic effects are, however, not yet investigated. AIM OF THE STUDY: The aim of this study is to carry out a detailed chemical investigation of Olax mannii leaves and the effects of the isolated constituents on the nuclear factor kappa B (NF-κB) pathway. MATERIALS AND METHODS: A methanol leaf extract was subjected to various chromatographic separations to achieve isolation of flavonoid glycosides and the structures of the isolated compounds were elucidated by a combination of 1D and 2D NMR and high resolution mass spectrometry. Biological activities were assessed by measurement of cellular viability and proliferation using quantitative IncuCyte videomicroscopy, trypan blue staining and by quantification of the number of metabolically active K562 cells based on quantitation of ATP. The effect of the compounds on the inhibition of the NF-κB pathway as well as toxicity towards peripheral blood mononuclear cells to evaluate differential toxicity was also assayed. RESULTS: Chemical investigation of the methanol leaf extract of the plant material led to the isolation of three new flavonoid triglycosides, kaempferol 3-O-[α-D-apiofuranosyl-(1 → 2)-α-L-arabinofuranoside]-7-O-α-L-rhamnopyranoside (1), kaempferol 3-O-[ß-D-glucopyranosyl-(1 → 2)-α-L-arabinofuranoside]-7-O-α-L-rhamnopyranoside (2), kaempferol 3-O-[ß-D-arabinopyranosyl-(1→4)-α-L-rhamnopyranoside]-7-O-α-L-rhamnopyranoside (3), in addition to fourteen known flavonoid glycosides (4-17). Of all the tested compounds, only compound 9 (kaempferol 3-O-α-L-rhamnopyranoside) exhibited promising and specific antiproliferative activity on human K562 chronic myelogenous leukemia cells and dose-dependently inhibited NF-κB transactivation. CONCLUSION: The presence of this flavonoid glycoside and derivatives may account for the reported efficacy of Olax mannii leaf extract in the ethnomedicinal management of cancer and inflammation.


Assuntos
Flavonoides/farmacologia , Glicosídeos/farmacologia , NF-kappa B/metabolismo , Olacaceae , Sobrevivência Celular/efeitos dos fármacos , Flavonoides/análise , Flavonoides/química , Glicosídeos/análise , Glicosídeos/química , Humanos , Células K562 , Estrutura Molecular , Folhas de Planta/química , Transdução de Sinais/efeitos dos fármacos
4.
Z Naturforsch C J Biosci ; 70(3-4): 75-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26052135

RESUMO

Chemical investigation of an unknown marine sponge, which was collected in the Gulf of Aqaba (Jordan), afforded a new brominated alkaloid 3-amino-1-(2-amino-4-bromophenyl)propan-1-one (1), as well as 7-bromoquinolin-4(1H)-one (2) which had previously only been reported as a synthetic compound. In addition, caulerpin (6), previously only known to be produced by algae, was likewise isolated. Furthermore, three known alkaloids including (Z)-5-(4-hydroxybenzylidene)-hydantoin, (Z)-6-bromo-3'-deimino-2',4'-bis(demethyl)-3'-oxoaplysinopsin, and 6-bromoindole-3-carbaldehyde (3-5), were also obtained. All compounds were unambiguously elucidated based on extensive 1D and 2D NMR spectroscopy, LCMS, as well as by comparison with the literature and tested for their cytotoxic activity toward the mouse lymphoma cell line L5178Y.


Assuntos
Alcaloides/química , Compostos de Nitrogênio/química , Poríferos/química , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Animais , Linhagem Celular Tumoral , Camundongos , Compostos de Nitrogênio/isolamento & purificação , Compostos de Nitrogênio/farmacologia
5.
Bioorg Med Chem ; 23(4): 712-9, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25600409

RESUMO

The soil fungus Gymnascella dankaliensis was collected in the vicinity of the Giza pyramids, Egypt. When grown on solid rice medium the fungus yielded four new compounds including 11'-carboxygymnastatin N (1), gymnastatin S (2), dankamide (3), and aranorosin-2-methylether (4), the latter having been reported previously only as a semisynthetic compound. In addition, six known metabolites (5-10) were isolated. Addition of NaCl or KBr to the rice medium resulted in the accumulation of chlorinated or brominated compounds as indicated by LC-MS analysis due to the characteristic isotope patterns observed. From the rice medium spiked with 3.5% NaCl the known chlorinated compounds gymnastatin A (11) and gymnastatin B (12) were obtained. All isolated compounds were unambiguously structurally elucidated on the basis of comprehensive spectral analysis (1D and 2D NMR, and mass spectrometry), as well as by comparison with the literature. Compounds 4, 7 and 11 showed potent cytotoxicity against the murine lymphoma cell line L5178Y (IC50 values 0.44, 0.58 and 0.64µM, respectively), whereas 12 exhibited moderate activity with an IC50 value of 5.80µM.


Assuntos
Amidas/química , Amidas/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Ascomicetos/química , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Acilação , Amidas/isolamento & purificação , Animais , Antineoplásicos/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Ensaios de Seleção de Medicamentos Antitumorais , Linfoma/tratamento farmacológico , Camundongos , Microbiologia do Solo
6.
Bioorg Med Chem ; 23(1): 126-31, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25482429

RESUMO

Chemical investigation of the EtOAc extract of the fungus Chaetomium aureum, an endophyte of the Moroccan medicinal plant Thymelaea lythroides, afforded one new resorcinol derivative named chaetorcinol, together with five known metabolites. The structures of the isolated compounds were determined on the basis of one- and two-dimensional NMR spectroscopy and high-resolution mass spectrometry as well as by comparison with the literature. All compounds were tested for their activity towards the Hsp90 chaperoning machine in vitro using the progesterone receptor (PR) and rabbit reticulocyte lysate (RRL). Among the isolated compounds, only sclerotiorin efficiently inhibited the Hsp90 machine chaperoning activity. However, sclerotiorin showed no cytotoxic effect on breast cancer Hs578T, MDA-MB-231 and prostate cancer LNCaP cell lines. Interestingly, deacetylation of sclerotiorin increased its cytotoxicity toward the tested cell lines over a period of 48 h.


Assuntos
Chaetomium/química , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Resorcinóis/química , Resorcinóis/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Feminino , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Coelhos
7.
Mar Drugs ; 12(2): 1043-65, 2014 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-24549204

RESUMO

Marine-derived bacteria and fungi are promising sources of novel bioactive compounds that are important for drug discovery programs. However, as encountered in terrestrial microorganisms there is a high rate of redundancy that results in the frequent re-discovery of known compounds. Apparently only a part of the biosynthetic genes that are harbored by fungi and bacteria are transcribed under routine laboratory conditions which involve cultivation of axenic microbial strains. Many biosynthetic genes remain silent and are not expressed in vitro thereby seriously limiting the chemical diversity of microbial compounds that can be obtained through fermentation. In contrast to this, co-cultivation (also called mixed fermentation) of two or more different microorganisms tries to mimic the ecological situation where microorganisms always co-exist within complex microbial communities. The competition or antagonism experienced during co-cultivation is shown to lead to a significantly enhanced production of constitutively present compounds and/or to an accumulation of cryptic compounds that are not detected in axenic cultures of the producing strain. This review highlights the power of co-cultivation for increasing the chemical diversity of bacteria and fungi drawing on published studies from the marine and from the terrestrial habitat alike.


Assuntos
Bactérias/química , Técnicas de Cocultura/métodos , Fungos/química , Biodiversidade , Produtos Biológicos/isolamento & purificação , Descoberta de Drogas/métodos , Fermentação
8.
J Nat Prod ; 77(2): 218-26, 2014 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-24479418

RESUMO

Chemical investigation of the sponge Dactylospongia metachromia afforded five new sesquiterpene aminoquinones (1-5), two new sesquiterpene benzoxazoles (6 and 7), the known analogue 18-hydroxy-5-epi-hyrtiophenol (8), and a known glycerolipid. The structures of all compounds were unambiguously elucidated by one- and two-dimensional NMR and by MS analyses, as well as by comparison with the literature. Compounds 1-5 showed potent cytotoxicity against the mouse lymphoma cell line L5178Y with IC50 values ranging from 1.1 to 3.7 µM. When tested in vitro for their inhibitory potential against 16 different protein kinases, compounds 5, 6, and 8 exhibited the strongest inhibitory activity against ALK, FAK, IGF1-R, SRC, VEGF-R2, Aurora-B, MET wt, and NEK6 kinases (IC50 0.97-8.62 µM).


Assuntos
Antineoplásicos/isolamento & purificação , Benzoxazóis/isolamento & purificação , Poríferos/química , Inibidores de Proteínas Quinases/isolamento & purificação , Quinonas/isolamento & purificação , Sesquiterpenos/isolamento & purificação , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Benzoxazóis/química , Benzoxazóis/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração Inibidora 50 , Biologia Marinha , Camundongos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Quinonas/química , Quinonas/farmacologia , Sesquiterpenos/química , Sesquiterpenos/farmacologia
9.
J Nat Prod ; 77(1): 49-56, 2014 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-24328302

RESUMO

A chemical investigation of the endophytic fungus Epicoccum nigrum isolated from leaves of Mentha suaveolens collected in Morocco resulted in the isolation of five new polyketides, epicocconigrones A and B (1 and 2), 3-methoxyepicoccone B (3), 3-methoxyepicoccone (4), and 2,3,4-trihydroxy-6-(methoxymethyl)-5-methylbenzaldehyde (5), together with five known compounds (6-10). The structures of the new compounds were unambiguously determined by extensive analysis of the 1D and 2D NMR and mass spectroscopic data. Compounds 1 and 10 showed potent inhibition of at least 15 protein kinases with IC50 values ranging from 0.07 to 9.00 µM. Moreover, compounds 1 and 10 inhibited histone deacetylase (HDAC) activities with IC50 values of 9.8 and 14.2 µM, respectively. A preliminary structure-activity relationship is discussed. Interestingly, compounds 1 and 10 exert mainly cytostatic effects in human lymphoma RAJI and U-937 cell lines.


Assuntos
Ascomicetos/química , Inibidores de Histona Desacetilases/isolamento & purificação , Inibidores de Histona Desacetilases/farmacologia , Mentha/microbiologia , Policetídeos/isolamento & purificação , Policetídeos/farmacologia , Inibidores de Proteínas Quinases/isolamento & purificação , Inibidores de Proteínas Quinases/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores de Histona Desacetilases/química , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Marrocos , Ressonância Magnética Nuclear Biomolecular , Folhas de Planta/microbiologia , Policetídeos/química , Inibidores de Proteínas Quinases/química , Proteínas Quinases , Relação Estrutura-Atividade
10.
J Org Chem ; 78(24): 12409-25, 2013 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-24295452

RESUMO

Four tetrahydroxanthone dimers (1-4) and four biogenetically related monomers (5-8), including the new derivatives 4-6, were isolated from the endophyte Phomopsis longicolla. The absolute configurations of 2-4 were established for the first time by TDDFT electronic circular dichroism calculations, and that of phomoxanthone A (1) was revised by X-ray crystallography. Phomoxanthone A (1) showed the strongest pro-apoptotic activity when tested against a panel of human cancer cell lines, including cisplatin-resistant cells, whereas it was up to 100-fold less active against healthy blood cells. It was also the most potent activator of murine T lymphocytes, NK cells, and macrophages, suggesting an activation of the immune system in parallel to its pro-apoptotic activity. This dual effect in combating cancer cells could help in fighting resistance during chemotherapy. Preliminary structure-activity studies of isolated compounds and derivatives obtained by semisynthesis (9a-11) hinted at the location of the biaryl axis and the presence of acetyl groups as important structural elements for the biological activity of the studied tetrahydroxanthones.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ascomicetos/química , Xantonas/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Apoptose/imunologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dimerização , Relação Dose-Resposta a Droga , Humanos , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Modelos Moleculares , Estrutura Molecular , Teoria Quântica , Relação Estrutura-Atividade , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Xantonas/química , Xantonas/isolamento & purificação
12.
Bioorg Med Chem ; 21(13): 3850-8, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23664494

RESUMO

Altersolanol A, a natural product from the endophytic fungus Stemphylium globuliferum isolated from the medicinal plant Mentha pulegium (Lamiaceae) growing in Morocco, shows cytotoxic, cytostatic, anti-inflammatory and anti-migrative activity against human chronic myeloid K562 leukemia and A549 lung cancer cells in a dose dependent manner without affecting the viability of non cancerous cells. Altersolanol A induces cell death by apoptosis through the cleavage of caspase-3 and -9 and through the decrease of anti-apoptotic protein expression. Moreover, we report here the importance of the distinct structural features of altersolanol A by testing other related anthracene derivatives in order to identify preliminary structure-activity relationships. Acetylation of altersolanol A did not improve activity where other derivatives such as tetrahydroaltersolanol B and ampelanol that differ from altersolanol A by reduction of one of a carbonyl group and removal of hydroxyl substituents were inactive in comparison. Altogether our results suggest that altersolanol A may be considered as an interesting lead for further development of chemotherapeutic agents.


Assuntos
Antraquinonas/farmacologia , Anti-Inflamatórios/farmacologia , Antineoplásicos/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , NF-kappa B/antagonistas & inibidores , Antraquinonas/química , Antraquinonas/isolamento & purificação , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Ascomicetos/química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Mentha pulegium/microbiologia , NF-kappa B/imunologia , Fator de Necrose Tumoral alfa/imunologia
13.
J Med Chem ; 56(7): 2991-9, 2013 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-23484593

RESUMO

Two new metabolites, embellicines A and B (1 and 2), were isolated from the EtOAc extract of the fungus Embellisia eureka , an endophyte of the Moroccan plant Cladanthus arabicus (Asteraceae). The structures of these new compounds were determined on the basis of extensive one- and two-dimensional NMR spectroscopy as well as by high-resolution mass spectrometry. The absolute configuration of embellicine A (1) was determined by TDDFT ECD calculations of solution conformers, whereas that of embellicine B (2) was deduced based on ROESY correlations and on biogenetic considerations in comparison to 1. Both embellicines (1 and 2) are cytostatic, cytotoxic, and inhibit NF-κB transcriptional activity, indicating that inhibition of NF-κB may be a possible mechanism of action of these compounds. Embellicine B (2) was the most active compound encountered in this study and acts at nanomolar concentrations without affecting tumor microenvironment.


Assuntos
Indanos/farmacologia , NF-kappa B/antagonistas & inibidores , Pirrolidinonas/farmacologia , Transcrição Gênica/efeitos dos fármacos , Indanos/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Modelos Moleculares , Pirrolidinonas/química , Espectrometria de Massas por Ionização por Electrospray
14.
J Med Chem ; 56(8): 3257-72, 2013 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-23534483

RESUMO

Two bisdihydroanthracenone atropodiastereomeric pairs, including homodimeric flavomannin A (1) and the previously unreported flavomannin B (2), two new unsymmetrical dimers (3 and 4), and two new mixed dihydroanthracenone/anthraquinone dimers (5 and 6) were isolated from Talaromyces wortmannii , an endophyte of Aloe vera . The structures of 2-6 were elucidated by extensive NMR and mass spectrometric analyses. The axial chirality of the biaryls was determined using TDDFT ECD and VCD calculations, the combination of which however did not allow the assignment of the central chirality elements of 1. The compounds exhibited antibacterial activity against Staphylococcus aureus , including (multi)drug-resistant clinical isolates. Reporter gene analyses indicated induction of the SOS response for some of the derivatives, suggesting interference with DNA structure or metabolism. Fluorescence microscopy demonstrated defective segregation of the bacterial chromosome and DNA degradation. Notably, the compounds showed no cytotoxic activity, encouraging their further evaluation as potential starting points for antibacterial drug development.


Assuntos
Antracenos/isolamento & purificação , Antibacterianos/isolamento & purificação , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Aloe/microbiologia , Animais , Antracenos/química , Antracenos/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Células 3T3 BALB , Linhagem Celular Tumoral , DNA Bacteriano/efeitos dos fármacos , Endófitos/química , Eurotiales/química , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Ressonância Magnética Nuclear Biomolecular , Resposta SOS em Genética/efeitos dos fármacos , Estereoisomerismo
15.
Chirality ; 25(4): 250-6, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23532999

RESUMO

Three new polyketides ((-)-1, (+)-1, and 2) were isolated from the EtOAc extract of the fungus Embellisia eureka, an endophyte of the Moroccan plant Cladanthus arabicus (Asteraceae). The structures of these new compounds were determined on the basis of one- and two-dimensional NMR spectroscopy as well as by high-resolution mass spectrometry. The absolute configurations of (-)-1, (+)-1, and 2 were determined by TDDFT ECD calculations of solution conformers, online HPLC-ECD analysis, and the modified Mosher method.


Assuntos
Alternaria/química , Alternaria/fisiologia , Asteraceae/microbiologia , Endófitos/química , Endófitos/fisiologia , Compostos Heterocíclicos/química , Compostos Heterocíclicos/isolamento & purificação , Modelos Moleculares , Conformação Molecular
16.
Cancer Discov ; 3(1): 68-81, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23103855

RESUMO

UNLABELLED: Inhibition of PARP is a promising therapeutic strategy for homologous recombination-deficient tumors, such as BRCA1-associated cancers. We previously reported that BRCA1-deficient mouse mammary tumors may acquire resistance to the clinical PARP inhibitor (PARPi) olaparib through activation of the P-glycoprotein drug efflux transporter. Here, we show that tumor-specific genetic inactivation of P-glycoprotein increases the long-term response of BRCA1-deficient mouse mammary tumors to olaparib, but these tumors eventually developed PARPi resistance. In a fraction of cases, this resistance is caused by partial restoration of homologous recombination due to somatic loss of 53BP1. Importantly, PARPi resistance was minimized by long-term treatment with the novel PARP inhibitor AZD2461, which is a poor P-glycoprotein substrate. Together, our data suggest that restoration of homologous recombination is an important mechanism for PARPi resistance in BRCA1-deficient mammary tumors and that the risk of relapse of BRCA1-deficient tumors can be effectively minimized by using optimized PARP inhibitors. SIGNIFICANCE: In this study, we show that loss of 53BP1 causes resistance to PARP inhibition in mouse mammary tumors that are deficient in BRCA1. We hypothesize that low expression or absence of 53BP1 also reduces the response of patients with BRCA1-deficient tumors to PARP inhibitors.


Assuntos
Antineoplásicos/uso terapêutico , Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA/genética , Resistencia a Medicamentos Antineoplásicos , Inibidores Enzimáticos/uso terapêutico , Ftalazinas/uso terapêutico , Piperazinas/uso terapêutico , Piperidinas/uso terapêutico , Inibidores de Poli(ADP-Ribose) Polimerases , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/deficiência , Animais , Proteína BRCA1/genética , Linhagem Celular Tumoral , Dano ao DNA , Feminino , Neoplasias Mamárias Animais/tratamento farmacológico , Camundongos , Mutação , Proteína 1 de Ligação à Proteína Supressora de Tumor p53
17.
Pediatr Dent ; 34(2): e35-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22583875

RESUMO

PURPOSE: Distraction is one of the most commonly used techniques for control of pain associated with injection procedures. This study's purpose was to evaluate the effect of a distraction technique using audiovisual (A/V) glasses on pain perception during administration of local anesthesia for children. METHODS: Forty-eight healthy, cooperative 5- to 7-year-olds were selected on the basis of existence of bilateral carious primary mandibular molars, which necessitated an inferior alveolar nerve block anesthesia before treatment. Treatment was done on 2 visits 1 week apart. Children had been randomly assigned to receive the A/V glasses at one visit and no distraction during the other visit. Two different pain assessment scales were used: the pain faces scale (PFS) and the face, legs, activity, cry, and consolability scale (FLACC) scale. Kappa statistics were calculated for the reliability of the observer when using the FLACC scale. A comparison between the 2 study techniques was done using the Wilcoxon signed ranks test. RESULTS: Kappa values ranged from 0.89 to 1.00. The pain scores in both scales were significantly lower when the A/V glasses were used. CONCLUSION: Distraction induced by audiovisual glasses was an effective way to reduce the pain associated with injection of local anesthesia.


Assuntos
Anestésicos Locais/administração & dosagem , Dor/prevenção & controle , Anestésicos Locais/efeitos adversos , Criança , Pré-Escolar , Humanos , Dor/psicologia , Medição da Dor
18.
Int J Radiat Oncol Biol Phys ; 83(5): e677-83, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22520477

RESUMO

PURPOSE: To investigate whether the expression of p53 binding protein 1 (53BP1) has prognostic significance in a cohort of early-stage breast cancer patients treated with breast-conserving surgery and radiotherapy (BCS+RT). METHODS AND MATERIALS: A tissue microarray of early-stage breast cancer treated with BCS+RT from a cohort of 514 women was assayed for 53BP1, estrogen receptor, progesterone receptor, and HER2 expression by immunohistochemistry. Through log-rank tests and univariate and multivariate models, the staining profile of each tumor was correlated with clinical endpoints, including ipsilateral breast recurrence-free survival (IBRFS), distant metastasis-free survival (DMFS), cause-specific survival (CSS), recurrence-free survival (RFS), and overall survival (OS). RESULTS: Of the 477 (93%) evaluable tumors, 63 (13%) were scored as low. Low expression of 53BP1 was associated with worse outcomes for all endpoints studied, including 10-year IBRFS (76.8% vs. 90.5%; P=.01), OS (66.4% vs. 81.7%; P=.02), CSS (66.0% vs. 87.4%; P<.01), DMFS (55.9% vs. 87.0%; P<.01), and RFS (45.2% vs. 80.6%; P<.01). Multivariate analysis incorporating various clinico-pathologic markers and 53BP1 expression found that 53BP1 expression was again an independent predictor of all endpoints (IBRFS: P=.0254; OS: P=.0094; CSS: P=.0033; DMFS: P=.0006; RFS: P=.0002). Low 53BP1 expression was also found to correlate with triple-negative (TN) phenotype (P<.01). Furthermore, in subset analysis of all TN breast cancer, negative 53BP1 expression trended for lower IBRFS (72.3% vs. 93.9%; P=.0361) and was significant for worse DMFS (48.2% vs. 86.8%; P=.0035) and RFS (37.8% vs. 83.7%; P=.0014). CONCLUSION: Our data indicate that low 53BP1 expression is an independent prognostic indicator for local relapse among other endpoints in early-stage breast cancer and TN breast cancer patients treated with BCS+RT. These results should be verified in larger cohorts of patients to validate their clinical significance.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/terapia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mastectomia Segmentar , Proteínas de Neoplasias/metabolismo , Recidiva Local de Neoplasia/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Terapia Combinada/métodos , Intervalo Livre de Doença , Feminino , Humanos , Pessoa de Meia-Idade , Análise Multivariada , Recidiva Local de Neoplasia/mortalidade , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Estudos Retrospectivos , Análise Serial de Tecidos , Resultado do Tratamento , Proteína 1 de Ligação à Proteína Supressora de Tumor p53
19.
Appl Microbiol Biotechnol ; 90(6): 1829-45, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21523479

RESUMO

Fungal endophytes residing in the internal tissues of living plants occur in almost every plant on earth from the arctic to the tropics. The endophyte-host relationship is described as a balanced symbiotic continuum ranging from mutualism through commensalism to parasitism. This overview will highlight selected aspects of endophyte diversity, host specificity, endophyte-host interaction and communication as well as regulation of secondary metabolite production with emphasis on advanced genomic methods and their role in improving our current knowledge of endophytic associations. Furthermore, the chemical potential of endophytic fungi for drug discovery will be discussed with focus on the detection of pharmaceutically valuable plant constituents as products of fungal biosynthesis. In addition, selected examples of bioactive metabolites reported in recent years (2008-2010) from fungal endophytes residing in terrestrial plants are presented grouped according to their reported biological activities.


Assuntos
Fungos/fisiologia , Plantas/microbiologia , Simbiose , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Especificidade de Hospedeiro , Metabolismo
20.
J Mol Cell Biol ; 3(1): 66-74, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21278454

RESUMO

BRCA1 plays a critical role in the regulation of homologous recombination (HR)-mediated DNA double-strand break repair. BRCA1-deficient cancers have evolved to tolerate loss of BRCA1 function. This renders them vulnerable to agents, such as PARP inhibitors, that are conditionally 'synthetic lethal' with their underlying repair defect. Recent studies demonstrate that BRCA1-deficient cells may acquire resistance to these agents by partially correcting their defect in HR-mediated repair, either through reversion mutations in BRCA1 or through 'synthetic viable' loss of 53BP1. These findings and their clinical implications will be reviewed in this article.


Assuntos
Proteína BRCA1/genética , Genes Letais/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Poli(ADP-Ribose) Polimerases/genética , Animais , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Resistencia a Medicamentos Antineoplásicos , Humanos , Neoplasias/genética , Poli(ADP-Ribose) Polimerases/metabolismo , Recombinação Genética , Proteína 1 de Ligação à Proteína Supressora de Tumor p53
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