Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
Más filtros










Intervalo de año de publicación
1.
Braz. j. biol ; 842024.
Artículo en Inglés | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469316

RESUMEN

Abstract The antioxidant activity of Tetragonisca angustula honey (TAH) and its ethanolic extract (TAEE) were investigated. The total levels of phenolic (TPC) and flavonoids (TFC) were also evaluated. The results for TPC were 19.91 ± 0.38 and 29.37 ± 1.82 mg GAE g-1 and for TFC 0.20 ± 0.02 and 0.14 ± 0.01 mg QE g-1 of TAH and TAEE, respectively. Antioxidant activities were 73.29 ± 0.49% and 93.36 ± 0.27% in the DPPH assay and 71.73 ± 4.07% and 97.86 ± 0.35% in ABTS+ for TAH and TAEE, respectively. The total reducing activity was determined by the method of reducing power (PR) and iron ion (Fe III) and the results varied in PR from 151.7 ± 25.7 and 230.7 ± 25.2 mg GAE L-1, for TAH and TAEE respectively and for (Fe III) in EC50 0.284 in TAEE and 0.687 in TAH. Chemical analysis by HPLC-DAD of the ethanolic extract (TAEE) revealed the presence of ferulic acid as majority phenolic component in the extract. The 1H NMR analysis confirmed this structure and showed the also presence of glucose, citric acid, succinic acid, proline and hydrocarbon derivatives. In addition, the botanical origin was also investigated and showed a multifloral characteristic, having found 19 pollen types with a botanical predominance of the Anacardiaceae family, with Tapirira pollen occurring as predominant (42.6%) and Schinus as secondary (25.7%). The results showed that T. angustula honey is an interesting source of antioxidant phenolic compounds due to its floral origin and can act as a protector of human health when consumed.


Resumo A atividade antioxidante do mel de Tetragonisca angustula (TAH) e seu extrato etanólico (TAEE) foram investigados. Os níveis totais de fenólicos (TPC) e flavonóides (TFC) também foram avaliados. Os resultados para TPC foram 19,91 ± 0,38 e 29,37 ± 1,82 mg GAE g-1 e para TFC 0,20 ± 0,02 e 0,14 ± 0,01 mg QE g-1 de TAH e TAEE, respectivamente. As atividades antioxidantes foram 73,29 ± 0,49% e 93,36 ± 0,27% no ensaio DPPH e 71,73 ± 4,07% e 97,86 ± 0,35% no ABTS+ para TAH e TAEE, respectivamente. A atividade redutora total foi determinada pelo método de poder redutor (PR) e íon ferrico (Fe III) e os resultados variaram em PR de 151,7 ± 25,7 e 230,7 ± 25,2 mg GAE L-1, para TAH e TAEE respectivamente e para (Fe III) em EC50 0,284 em TAEE e 0,687 em TAH. A análise química por HPLC-DAD do extrato etanólico (TAEE) revelou a presença de ácido ferúlico como componente majoritário no extrato. A análise de RMN 1H confirmou esta estrutura e mostrou a presença de glicose, ácido cítrico, ácido succínico, prolina e derivados de hidrocarbonetos no TAEE. Além disso, a origem botânica também foi investigada e apresentou característica multifloral, tendo encontrado 19 tipos polínicos com predomínio botânico da família Anacardiaceae, sendo o pólen Tapirira predominante (42,6%) e o Schinus secundário (25,7%). Os resultados mostraram que o mel de T. angustula é uma interessante fonte de compostos fenólicos antioxidantes devido à sua origem floral e pode atuar como protetor da saúde humana quando consumido.

2.
Braz. j. biol ; 84: e253599, 2024. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1355891

RESUMEN

Abstract The antioxidant activity of Tetragonisca angustula honey (TAH) and its ethanolic extract (TAEE) were investigated. The total levels of phenolic (TPC) and flavonoids (TFC) were also evaluated. The results for TPC were 19.91 ± 0.38 and 29.37 ± 1.82 mg GAE g-1 and for TFC 0.20 ± 0.02 and 0.14 ± 0.01 mg QE g-1 of TAH and TAEE, respectively. Antioxidant activities were 73.29 ± 0.49% and 93.36 ± 0.27% in the DPPH● assay and 71.73 ± 4.07% and 97.86 ± 0.35% in ABTS●+ for TAH and TAEE, respectively. The total reducing activity was determined by the method of reducing power (PR) and iron ion (Fe III) and the results varied in PR from 151.7 ± 25.7 and 230.7 ± 25.2 mg GAE L-1, for TAH and TAEE respectively and for (Fe III) in EC50 0.284 in TAEE and 0.687 in TAH. Chemical analysis by HPLC-DAD of the ethanolic extract (TAEE) revealed the presence of ferulic acid as majority phenolic component in the extract. The 1H NMR analysis confirmed this structure and showed the also presence of glucose, citric acid, succinic acid, proline and hydrocarbon derivatives. In addition, the botanical origin was also investigated and showed a multifloral characteristic, having found 19 pollen types with a botanical predominance of the Anacardiaceae family, with Tapirira pollen occurring as predominant (42.6%) and Schinus as secondary (25.7%). The results showed that T. angustula honey is an interesting source of antioxidant phenolic compounds due to its floral origin and can act as a protector of human health when consumed.


Resumo A atividade antioxidante do mel de Tetragonisca angustula (TAH) e seu extrato etanólico (TAEE) foram investigados. Os níveis totais de fenólicos (TPC) e flavonóides (TFC) também foram avaliados. Os resultados para TPC foram 19,91 ± 0,38 e 29,37 ± 1,82 mg GAE g-1 e para TFC 0,20 ± 0,02 e 0,14 ± 0,01 mg QE g-1 de TAH e TAEE, respectivamente. As atividades antioxidantes foram 73,29 ± 0,49% e 93,36 ± 0,27% no ensaio DPPH● e 71,73 ± 4,07% e 97,86 ± 0,35% no ABTS●+ para TAH e TAEE, respectivamente. A atividade redutora total foi determinada pelo método de poder redutor (PR) e íon ferrico (Fe III) e os resultados variaram em PR de 151,7 ± 25,7 e 230,7 ± 25,2 mg GAE L-1, para TAH e TAEE respectivamente e para (Fe III) em EC50 0,284 em TAEE e 0,687 em TAH. A análise química por HPLC-DAD do extrato etanólico (TAEE) revelou a presença de ácido ferúlico como componente majoritário no extrato. A análise de RMN 1H confirmou esta estrutura e mostrou a presença de glicose, ácido cítrico, ácido succínico, prolina e derivados de hidrocarbonetos no TAEE. Além disso, a origem botânica também foi investigada e apresentou característica multifloral, tendo encontrado 19 tipos polínicos com predomínio botânico da família Anacardiaceae, sendo o pólen Tapirira predominante (42,6%) e o Schinus secundário (25,7%). Os resultados mostraram que o mel de T. angustula é uma interessante fonte de compostos fenólicos antioxidantes devido à sua origem floral e pode atuar como protetor da saúde humana quando consumido.


Asunto(s)
Humanos , Animales , Miel/análisis , Antioxidantes , Fenoles/análisis , Brasil , Ácidos Cumáricos
3.
Braz J Biol ; 84: e253599, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35019099

RESUMEN

The antioxidant activity of Tetragonisca angustula honey (TAH) and its ethanolic extract (TAEE) were investigated. The total levels of phenolic (TPC) and flavonoids (TFC) were also evaluated. The results for TPC were 19.91 ± 0.38 and 29.37 ± 1.82 mg GAE g-1 and for TFC 0.20 ± 0.02 and 0.14 ± 0.01 mg QE g-1 of TAH and TAEE, respectively. Antioxidant activities were 73.29 ± 0.49% and 93.36 ± 0.27% in the DPPH● assay and 71.73 ± 4.07% and 97.86 ± 0.35% in ABTS●+ for TAH and TAEE, respectively. The total reducing activity was determined by the method of reducing power (PR) and iron ion (Fe III) and the results varied in PR from 151.7 ± 25.7 and 230.7 ± 25.2 mg GAE L-1, for TAH and TAEE respectively and for (Fe III) in EC50 0.284 in TAEE and 0.687 in TAH. Chemical analysis by HPLC-DAD of the ethanolic extract (TAEE) revealed the presence of ferulic acid as majority phenolic component in the extract. The 1H NMR analysis confirmed this structure and showed the also presence of glucose, citric acid, succinic acid, proline and hydrocarbon derivatives. In addition, the botanical origin was also investigated and showed a multifloral characteristic, having found 19 pollen types with a botanical predominance of the Anacardiaceae family, with Tapirira pollen occurring as predominant (42.6%) and Schinus as secondary (25.7%). The results showed that T. angustula honey is an interesting source of antioxidant phenolic compounds due to its floral origin and can act as a protector of human health when consumed.


Asunto(s)
Antioxidantes , Miel , Animales , Brasil , Ácidos Cumáricos , Miel/análisis , Humanos , Fenoles/análisis
4.
J Ethnopharmacol ; 222: 177-189, 2018 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-29689352

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Myracrodruon urundeuva Allemão (Aroeira-do-Sertão), Anacardiaceae, is one of the most used plants in folk medicine in Northeastern Brazil as an anti-inflammatory, healing and antiulcer. This species is threatened with extinction due to anthropogenic exploitation. The importance of this study is to demonstrate the feasibility of a conservationist model of replacement of the M. urundeuva adult tree (inner bark) for its under developing plants (shoots) in order to ensure the preservation of this species, but also to ensure sufficient raw material for pharmaceutical purposes. AIM OF THE STUDY: To characterize chemically and assess the gastroprotective and anti-inflammatory activities of the fluid extracts from M. urundeuva innebark (adult plant) as well as stem and leaves of shoots (young plant). MATERIALS AND METHODS: The fluid extracts were prepared by maceration-percolation with hydroalcoholic solution according to the methodology described in the Brazilian Pharmacopoeia. These extracts were cleaned-up through solid phase extraction (SPE) and chemically characterized by ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-ESI-QTOF MS/MS). Gastroprotective and anti-inflammatory activities of the extracts (700 or 1000 mg/kg) were assessed on ethanol-induced gastric lesions and Croton oil-induced ear edema in rats, respectively. The extracts were evaluated for cytotoxicity in vitro. RESULTS: The UPLC-ESI-QTOF-MS/MS analysis evidenced the presence of chalcones, flavonoids and tannins. Gastroprotective and anti-inflammatory activities achieved with fluid extracts from the stems and leaves was similar to inner bark. The fluid extracts were not toxic. CONCLUSION: It is possible to replace the inner bark of the adult tree for the stems and leaves from the shoots as raw material to be used in the preparation of its the phytotherapeutics. Therefore, this finding may help in the implementation of public policies that ensure the conservation of the species along with its sustainable use for pharmaceutical purposes.


Asunto(s)
Anacardiaceae , Antiinflamatorios/uso terapéutico , Antiulcerosos/uso terapéutico , Extractos Vegetales/uso terapéutico , Animales , Antiinflamatorios/farmacología , Antiulcerosos/farmacología , Supervivencia Celular/efectos de los fármacos , Edema/inducido químicamente , Edema/tratamiento farmacológico , Etanol , Células HEK293 , Humanos , Ratones , Corteza de la Planta , Extractos Vegetales/farmacología , Hojas de la Planta , Tallos de la Planta , Úlcera Gástrica/tratamiento farmacológico
5.
J Helminthol ; 92(6): 674-680, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29067895

RESUMEN

This study describes the effects of extracts and fractions of Persea willdenovii leaves against goat gastrointestinal nematodes and their cytotoxicity on Vero cells. The in vitro ovicidal and larvicidal activities of the crude ethanolic, hexane, ethyl acetate (EAE), butanolic and residual hydroethanolic extracts were assessed through the inhibition of egg hatching and larval motility assays. The most active extract (EAE) was then fractionated by chromatography in an open column containing silica gel, to furnish six fractions (Fr1-Fr6), which were also tested. The cytotoxicity of active extracts and fractions was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and trypan blue exclusion assay. The EAE and two fractions (Fr1 and Fr2) showed inhibitory activity in the egg hatching of gastrointestinal nematodes of goats in a concentration-dependent manner. The effective concentrations for 50% inhibition (EC50) of egg hatching were 2.3, 0.12 and 2.94 mg/ml for EAE, Fr1 and Fr2, respectively. All extracts and fractions were not effective in inhibiting 50% of motility of infective larvae. EAE and Fr2 had IC50 values (50% inhibitory concentration) of 4.95 and 2.66 mg/ml, respectively. Fr1 showed a slight cytotoxic effect (cellular inviability <30%) only after 48 h of treatment (MTT test). Gas chromatography-mass spectrometry (GC-MS) analysis showed the presence of six fatty acid ethyl esters, a fatty acid methyl ester and a long-chain ketone in the most active fraction. These constituents identified in P. willdenovii can be related to the high ovicidal activity and relatively non-toxic effect of the extracts.


Asunto(s)
Antihelmínticos/farmacología , Antihelmínticos/toxicidad , Nematodos/efectos de los fármacos , Persea/química , Extractos Vegetales/farmacología , Extractos Vegetales/toxicidad , Animales , Antihelmínticos/química , Antihelmínticos/aislamiento & purificación , Bioensayo , Supervivencia Celular/efectos de los fármacos , Chlorocebus aethiops , Cromatografía de Gases y Espectrometría de Masas , Cabras , Concentración 50 Inhibidora , Larva/efectos de los fármacos , Larva/fisiología , Locomoción/efectos de los fármacos , Nematodos/fisiología , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta/química , Células Vero
6.
Rev. bras. plantas med ; 14(2): 287-292, 2012. ilus
Artículo en Inglés | LILACS | ID: lil-650668

RESUMEN

Spathodea campanulata is used in traditional medicine in Africa as diuretic and anti-inflammatory. Although few studies have reported the mechanism of antioxidant action, this study evidenced the antioxidant activity of S. campanulata bark and flower extracts and their possible mechanism of action. Ethanol extracts of S. campanulata bark and flowers showed antioxidant activity on lipid peroxidation of liver microsome induced by Fe3+-ascorbic acid. Bark extract was 5 times more efficient than flower extract. The antioxidant activity of flower extract, previously complexed with increasing concentrations of Fe3+ (20 - 100 µM) which resulted in antioxidant activity loss, was shown to be related to iron complex formation. In contrast, the antioxidant activity of bark extract was not inhibited by the previous incubation with Fe3+, although complexation was demonstrated by spectral analysis of the solution. These results suggest an antioxidant mechanism other than Fe3+ complex formation. Therefore, the antioxidant mechanisms of S. campanulata flower and bark extracts are distinct from each other, reflecting the extract heterogeneous composition and the mechanism of action.


Spathodea campanulata é usada na medicina popular na África como diurético e antiinflamatório. Embora poucos estudos relatem o mecanismo de ação antioxidante, neste trabalho foi evidenciado a atividade antioxidante dos extratos da casca e da flor da S. campanulata e o possível mecanismo de ação. Os extratos etanólicos da casca e da flor da S. campanulata mostrou possuir atividade antioxidante sobre a lipoperoxidação de microssoma hepático induzida por Fe3+-ácido ascórbico. O extrato da casca foi 5 vezes mais eficiente que da flor. O extrato da flor foi previamente complexado com concentrações crescentes de Fe3+ (20 - 100 µM) o qual resultou na perda da atividade antioxidante, demonstrando que esta está relacionada com a formação de complexo com o ferro. Por outro lado, a atividade antioxidante do extrato da casca não foi inibida pela prévia incubação com o ferro, embora haja a formação do complexo evidenciado pela análise espectral da solução. Estes resultados sugerem que o mecanismo antioxidante seja outro que não a complexação com o Fe3+. Portanto, o mecanismo antioxidante dos extratos da flor e da casca da S. campanulata é distinto entre si o que reflete a composição heterogênica do extrato e o mecanismo de ação.


Asunto(s)
Liriodendron/efectos adversos , Antioxidantes/análisis , Extractos Vegetales/análisis , Flores/efectos adversos
7.
Magn Reson Chem ; 47(6): 537-40, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19306481

RESUMEN

(1)H and (13)C NMR chemical shifts of praecansone B, pongaflavone and dehydrorotenone isolated from Tephrosia egregia Sandw and obovatin from T. toxicaria Pers. were unambiguously assigned by 1D and 2D NMR experiments including (1)H, (1)H COSY, gHMQC and gHMBC, allowing the correction of literature assignments.


Asunto(s)
Flavonas/química , Flavonoides/química , Protones , Tephrosia/química , Isótopos de Carbono , Flavonoides/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Estructura Molecular , Estándares de Referencia , Estereoisomerismo
8.
Rev. bras. farmacogn ; 15(3): 187-190, jul.-set. 2005. ilus, tab
Artículo en Portugués | LILACS | ID: lil-570909

RESUMEN

A atividade larvicida de quatro saponinas monodesmosídicas (1-4) isoladas de Pentaclethra macroloba e de uma saponina bidesmosídica (5) isolada de Cordia piauhiensis foi avaliada sobre larvas de estágio 3 de Aedes aegypti. As larvas foram expostas a várias concentrações (500, 250, 100, 50, 25 e 12,5 mg/mL) das saponinas por um período de 24 h. Os resultados indicam que somente as saponinas 1-3 mostraram alta atividade larvicida, com CL50 variando de 18,6 a 27,9 mg/mL. Estes resultados ressaltam as potencialidades destas saponinas como possíveis agentes larvicidas naturais.


The larvicidal activity of the four monodesmoside saponins (1-4) isolated from Pentaclethra macroloba and one bidesmoside saponin (5) from Cordia piauhiensis was evaluated on 3rd instar larvae of Aedes aegypti. The larvae were exposed to serial concentrations (500, 250, 100, 50, 25 and 12.5 mg/mL) saponins for a period of 24 h. The results indicate that, only the saponins 1-3 showed high larvicidal activity, with LC50 ranging of 18,6-27,9 mg/mL. These results suggest that these can be used as natural larvicidal agents.

9.
Rev. bras. farmacogn ; 15(1): 23-29, jan.-mar. 2005. ilus, graf, tab
Artículo en Portugués | LILACS | ID: lil-570878

RESUMEN

Das partes aéreas de Herissantia tiubae (K. Schum.) Brizicky foram isolados, através de métodos cromatográficos, dois flavonóides glicosilados, canferol 3,7-di-O-a-L-ramnopiranosídeo e canferol 3-b-O-D-(6’’-E-p-cumaroil) glicosídeo. As estruturas foram identificadas com o uso de técnicas espectroscópicas de IV, RMN ¹H e 13C incluindo métodos bidimensionais, além de comparações com dados da literatura. O canferol 3,7-di-O-a-L-ramnopiranosídeo foi submetido a testes farmacológicos preliminares com a finalidade de avaliar o seu efeito sobre o sistema cardiovascular.


From the aerial parts of Herissantia tiubae (K. Schum.) Brizicky two flavonol glycosides were isolated by means of chromatographic methods, kaempferol 3,7-di-O-a-L-rhamnopyranoside and kaempferol 3-O-b-D-(6’’-E-p-coumaroyl) glucoside. Their structural identification was made by IV, ¹H and 13C NMR spectroscopy, including two dimensional techniques, together with comparison with literatura data. Preliminary tests were carried out with kaempferol 3,7-di-O-a-L-rhamnopyranoside in order to study its possible cardiovascular effect.

10.
Rev. bras. farmacogn ; 15(1): 51-54, jan.-mar. 2005. ilus, tab
Artículo en Portugués | LILACS | ID: lil-570883

RESUMEN

O extrato metanólico das cascas do caule de Vitex gardneriana Schauer forneceu o ecdisteróide, 20-hidroxi-ecdisona e o iridóide glicosilado, aucubina. As estruturas foram caracterizadas por métodos químicos e espectroscópicos.


The methanolic extract of the stem bark of Vitex gardneriana Schauer afforded the ecdysteroid, 20-hydroxy-ecdysone and the iridoid glycoside, aucubin. Their structures were established on the basis of chemical and spectroscopic studies.

11.
Rev. bras. farmacogn ; 13(supl.1): 62-63, 2003. ilus
Artículo en Portugués | LILACS | ID: lil-526249

RESUMEN

Três alcalóides benzilisoquinolínicos, reticulina, coclaurina e N-acetilnorjuzifina foram isolados das cascas de caule de Ocotea duckei; do cálice foi isolado laureliptina, um alcalóide do tipo aporfínico. Essas substâncias foram isoladas por métodos cromatográficos e identificadas por espectroscopia de 1H e 13C NMR com o auxílio de técnicas 2-D como as de COSY, NOESY, HMQC e HMBC. Comparações com os dados de literatura foram também realizadas.


Three benzylisoquinoline alkaloids, reticuline, coclaurine, and N-acetyl norjuziphine, where isolated from the stem bark of Ocotea duckei, the calix yielded laurelliptine, an aporphine alkaloid. These substances were isolated by chromatographic methods and identified by 1H and 13C NMR spectroscopy with the aid of 2-D techniques such as COSY, NOESY, HMQC and HMBC. Comparison with literature data was also helpful.

12.
Rev. bras. farmacogn ; 13(supl.2): 44-46, 2003. ilus, tab
Artículo en Portugués | LILACS | ID: lil-526488

RESUMEN

O extrato hexânico das cascas do caule de Diplotropis ferruginea Benth (Fabaceae), após procedimentos cromatográficos e fitoquímicos, forneceu o triterpeno lupeol, citado pela primeira vez em Diplotropis ferruginea, e etil-2-hidroxi-4-methoxi-6-propil-benzoate, descrito pela primeira vez em na literatura. As determinações estruturais desses compostos foram realizadas com base em análises espectroscópicas de ¹H e 13C NMR, bem como também por comparação com valores da literatura.


The hexane extract of the stem bark of Diplotropis ferruginea Benth (Fabaceae), after chromatografic and phytochemical procedures, yielded the triterpene lupeol, wich has been cited for the first time on Diplotropis ferruginea, and ethyl-2-hydroxy-4-methoxy-6-propyl-benzoate, described for the first time on literature. The structural determinations of these compounds were performed on the basis of ¹H and 13C NMR spectroscopic analysis as well as comparison with literature values.

13.
Braz J Med Biol Res ; 35(7): 819-22, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12131922

RESUMEN

Topoisomerase inhibitors are agents with anticancer activity. 7"-O-Methyl-agathisflavone (I) and amentoflavone (II) are biflavonoids and were isolated from the Brazilian plants Ouratea hexasperma and O. semiserrata, respectively. These biflavonoids and the acetyl derivative of II (IIa) are inhibitors of human DNA topoisomerases I at 200 microM, as demonstrated by the relaxation assay of supercoiled DNA, and only agathisflavone (I) at 200 microM also inhibited DNA topoisomerases II-alpha, as observed by decatenation and relaxation assays. The biflavonoids showed concentration-dependent growth inhibitory activities on Ehrlich carcinoma cells in 45-h culture, assayed by a tetrazolium method, with IC50 = 24 +/- 1.4 microM for I, 26 +/- 1.1 microM for II and 10 +/- 0.7 microM for IIa. These biflavonoids were assayed against human K562 leukemia cells in 45-h culture, but only I showed 42% growth inhibitory activity at 90 microM. Our results suggest that biflavonoids are targets for DNA topoisomerases and their cytotoxicity is dependent on tumor cell type.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Inhibidores Enzimáticos/farmacología , Flavonoides/farmacología , Inhibidores de Topoisomerasa I , Animales , Antineoplásicos Fitogénicos/aislamiento & purificación , Brasil , Carcinoma de Ehrlich/tratamiento farmacológico , Carcinoma de Ehrlich/enzimología , Ensayos de Selección de Medicamentos Antitumorales , Electroforesis en Gel de Agar , Inhibidores Enzimáticos/aislamiento & purificación , Flavonoides/aislamiento & purificación , Humanos , Células K562/efectos de los fármacos , Leucemia/enzimología
14.
Braz. j. med. biol. res ; 35(7): 819-822, July 2002. ilus
Artículo en Inglés | LILACS | ID: lil-316736

RESUMEN

Topoisomerase inhibitors are agents with anticancer activity. 7"-O-Methyl-agathisflavone (I) and amentoflavone (II) are biflavonoids and were isolated from the Brazilian plants Ouratea hexasperma and O. semiserrata, respectively. These biflavonoids and the acetyl derivative of II (IIa) are inhibitors of human DNA topoisomerases I at 200 æM, as demonstrated by the relaxation assay of supercoiled DNA, and only agathisflavone (I) at 200 æM also inhibited DNA topoisomerases II-alpha, as observed by decatenation and relaxation assays. The biflavonoids showed concentration-dependent growth inhibitory activities on Ehrlich carcinoma cells in 45-h culture, assayed by a tetrazolium method, with IC50 = 24 ± 1.4 æM for I, 26 ± 1.1 æM for II and 10 ± 0.7 æM for IIa. These biflavonoids were assayed against human K562 leukemia cells in 45-h culture, but only I showed 42 percent growth inhibitory activity at 90 æM. Our results suggest that biflavonoids are targets for DNA topoisomerases and their cytotoxicity is dependent on tumor cell type


Asunto(s)
Humanos , Animales , Antineoplásicos Fitogénicos , ADN-Topoisomerasas de Tipo I , Inhibidores Enzimáticos , Flavonoides , Plantas , Antineoplásicos Fitogénicos , Brasil , Carcinoma de Ehrlich , Supervivencia Celular , Electroforesis en Gel de Agar , Inhibidores Enzimáticos , Flavonoides , Células K562 , Leucemia
15.
Phytochem Anal ; 12(4): 266-70, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11708300

RESUMEN

Further lipophilic flavonols present in Vellozia graminifolia have been determined by high temperature high resolution gas chromatography (HTHRGC) and by HTHRGC coupled to mass spectrometry (MS). These methods resulted in the detection, isolation and characterisation of a monoisoprenylated flavonol 3,5,4'-trimethoxy-3'-hydroxy-6,7-(2"-isopropenyldihydrofurano)flavone from the ethyl acetate extract of the whole plant. The structural elucidation was accomplished using spectral data, including two-dimensional NMR, and on chemical transformations. Both HTHRGC and HTHRGC-MS were shown to be alternative and extremely valuable methods for the quick screening of flavonoid aglycones and other chemical metabolites of the Velloziaceae.


Asunto(s)
Cromatografía de Gases/métodos , Flavonoides/análisis , Calor , Magnoliopsida/química , Flavonoles
16.
Fitoterapia ; 72(6): 715-6, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11543979

RESUMEN

The isolation of 1-hydroxy-3,7-dimethoxyxanthone (1) from Shultesia guianensis is reported along with relevant NMR spectra, including new data by two-dimensional NMR experiments (HMQC and HMBC).


Asunto(s)
Gentianaceae , Extractos Vegetales/química , Xantenos/química , Xantonas , Humanos , Espectroscopía de Resonancia Magnética
17.
J Nat Prod ; 64(6): 792-5, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11421746

RESUMEN

Eleven known compounds and a new prenylated naphthoquinone, lippsidoquinone (13), were isolated from ethanol extracts of Lippia sidoides. Their structures were established by a combination of 1D and 2D NMR, IR, and EIMS spectral data analysis. The cytotoxic properties of compounds 3--13 were evaluated against HL60, SW1573, and CEM cell lines. Only tectol (6) and lippsidoquinone (13) exhibited significant activity against human leukemia cell lines HL60 and CEM.


Asunto(s)
Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Naftoquinonas/química , Naftoquinonas/farmacología , Plantas Medicinales/química , Aedes , Animales , Antineoplásicos Fitogénicos/aislamiento & purificación , Biomphalaria , Brasil , Ensayos de Selección de Medicamentos Antitumorales , Insecticidas/química , Insecticidas/aislamiento & purificación , Insecticidas/toxicidad , Espectroscopía de Resonancia Magnética , Moluscocidas/química , Moluscocidas/aislamiento & purificación , Moluscocidas/toxicidad , Espectrofotometría Infrarroja , Células Tumorales Cultivadas
18.
Nat Prod Lett ; 15(4): 261-6, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11833621

RESUMEN

From the stem bark of Bowdichia virgilioides, lupeol, lupeol acetate, sitosterol, stigmasterol and methyl-3-[2-(1-hydroxymethylvinyl)-2,3-dihydrobenzo[b]furan-5-yl]-(E)-2-propenoate have been isolated. The latter is a new compound and it has been named as bowdenol. Their structures were elucidated with the aid of spectroscopic techniques, mostly 1 and 2D NMR. The biogenetic pathway for bowdenol has been suggested.


Asunto(s)
Benzofuranos/aislamiento & purificación , Fabaceae/química , Plantas Medicinales/química , Acrilatos/química , Acrilatos/metabolismo , Benzofuranos/química , Brasil , Catálisis , Cromatografía en Capa Delgada , Ácidos Cumáricos/química , Ácidos Cumáricos/metabolismo , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Corteza de la Planta/química , Tallos de la Planta/química , Ácido Shikímico/química , Ácido Shikímico/metabolismo , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Fosfatos de Azúcar/química , Fosfatos de Azúcar/metabolismo , Tirosina/química , Tirosina/metabolismo
19.
Fitoterapia ; 71(2): 211-2, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10727826

RESUMEN

The isolation and (13)C-NMR data of flavone derivatives from Bowdichia virgilioides roots are reported.


Asunto(s)
Extractos Vegetales/química , Plantas Medicinales , Flavonoides/química , Humanos , Raíces de Plantas
20.
Phytochemistry ; 55(7): 793-7, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11190398

RESUMEN

Three anthracene derivatives, auxenone, oncocalyxonol and auxemim, were isolated from Auxemma ontocalyx. The structures of these compounds as 1,4,8-trihydroxy-2-methoxy-5-methyl-9,10-anthraquinone, rel-9alpha,11alpha-epoxy-1,4,8alpha,11alpha-tetrahydroxy-2-methoxy-8a beta-methyl-5,6,7,8,8a,9, 10,10a beta-octahydro-10-anthracenone and rel-8alpha,11beta-epoxy-2,11-dimethoxy-8a beta-methyl-5,6,7,8,8a,9-hexahydro-1,4-anthracenedione were determined by analysis of spectral data (1D and 2D NMR, IR, HREIMS and UV).


Asunto(s)
Antracenos/aislamiento & purificación , Magnoliopsida/química , Antracenos/química , Estructura Molecular , Análisis Espectral
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...