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1.
J Vis Exp ; (133)2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29608154

RESUMO

Adventitious shoot formation is an important technique for the propagation of economically important crops and for the regeneration of transgenic plants. Phytohormone treatment is required for the induction of adventitious shoots in most species. Whether adventitious shoots can be induced is determined by the balance between auxin and cytokinin (CK) levels. Much effort goes into determining optimum concentrations and combinations of phytohormones in each tissue used as explants and in each plant species. In ipecac, however, adventitious shoots can be induced on internodal segments in culture medium without phytohormone treatment. This allows the inherent plasticity of ipecac for cell differentiation to be evaluated. To induce adventitious shoots in ipecac, we cultured internodal segments at 24 °C under 15 µmol m-2 s-1 of light in a 14-h light/10-h dark cycle on phytohormone-free B5 medium solidified with 0.2% gellan gum for 5 weeks. To investigate phytohormone dynamics during adventitious shoot formation, we measured endogenous indole-3-acetic acid and CKs in the segments by liquid chromatography-tandem mass spectrometry LC-MS/MS. This method allows analysis of endogenous indole-3-acetic acid and CKs levels in a simple manner. It can be applied to investigate the dynamics of endogenous auxin and CK during organogenesis in other plant species.


Assuntos
Cephaelis/metabolismo , Cromatografia Líquida/métodos , Citocininas/metabolismo , Ácidos Indolacéticos/metabolismo , Espectrometria de Massas em Tandem/métodos , Cephaelis/química , Citocininas/análise , Ácidos Indolacéticos/análise , Brotos de Planta/química , Brotos de Planta/metabolismo
2.
Yakugaku Zasshi ; 137(12): 1443-1482, 2017.
Artigo em Japonês | MEDLINE | ID: mdl-29199255

RESUMO

Studies on the structural determination, biosynthesis, and biological activities of secondary metabolites from natural sources are significant in the field of natural products chemistry. This review focuses on diverse secondary metabolites isolated from medicinal plants and cultivated mycobionts of lichens in our laboratory. Monoterpene-tetrahydroisoquinoline glycosides and alkaloids isolated from Cephaelis acuminata and Alangium lamarckii gave important information on the biosynthesis of ipecac alkaloids. A variety of glycosides linked with a secologanin unit and indole alkaloids were obtained from medicinal plants belonging to the families of Rubiaceae, Apocynaceae, and Loganiaceae. Plant species of the four genera Fraxinus, Syringa, Jasminum, and Ligustrum of the family Oleaceae were chemically investigated to provide several types of secoiridoid and iridoid glucosides. The biosynthetic pathway leading from protopine to benzophenanthridine alkaloids in suspension cell cultures of Eschscholtzia californica was elucidated. The structures and biological activities of the bisbenzylisoquinoline alkaloids of Stephania cepharantha and Nelumbo nucifera were also investigated. In addition, the mycobionts of lichens were cultivated to afford various types of metabolites that differ from the lichen substances of intact lichens but are structurally similar to fungal metabolites. The biosynthetic origins of some metabolites were also studied. These findings suggest that cultures of lichen mycobionts could be sources of new bioactive compounds and good systems for investigating secondary metabolism in lichens.


Assuntos
Alcaloides/isolamento & purificação , Glicosídeos/isolamento & purificação , Líquens/metabolismo , Plantas Medicinais/metabolismo , Alangiaceae/metabolismo , Alcaloides/biossíntese , Alcaloides/química , Benzilisoquinolinas , Cephaelis/metabolismo , Eschscholzia/metabolismo , Glicosídeos/biossíntese , Glicosídeos/química , Iridoides , Monoterpenos , Oleaceae/metabolismo , Rubiaceae/metabolismo , Stephania/metabolismo , Tetra-Hidroisoquinolinas
3.
Planta Med ; 82(11-12): 1009-15, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27145237

RESUMO

Human ether-a-go-go-related gene channel blocking is associated with QT interval prolongation and increased risk of potentially fatal arrhythmias. As natural products keep increasing in popularity, there is an urgent need for studies assessing human ether-a-go-go-related gene channel-related cardiotoxic risks. We selected 49 plant species based on the results of a pharmacophore-based virtual screening campaign, in parallel with a literature data survey concerning highly consumed herbal medicines with reported cardiac liabilities. Lead-like enhanced extracts were prepared, an initial in vitro screening was performed at 100 µg/mL by voltage clamp on Xenopus oocytes, and five human ether-a-go-go-related gene channel blocking extracts were identified. In accordance to the six virtually predicted alkaloids, the root extract of Carapichea ipecacuanha inhibited human ether-a-go-go-related gene channel currents by 32.5 %. A phytochemical workflow resulted in the isolation and identification of five out of the six virtually predicted alkaloids. All isolates blocked human ether-a-go-go-related gene channel currents to different extents. The major ipecac constituents emetine (1) and cephaeline (2) showed IC50 values of 21.4 and 5.3 µM, respectively, measured by whole-cell patch clamp in HEK293 cells. This is the first report on human ether-a-go-go-related gene channel blockers from C. ipecacuanha. Its roots and rhizomes are used to produce different pharmacopeial ipecac preparations that are mainly used as emetics for poisoning treatment. Our findings raise further questions regarding the safety and over-the-counter appropriateness of these herbal products.


Assuntos
Alcaloides/farmacologia , Cephaelis/química , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Ipeca/farmacologia , Alcaloides/química , Alcaloides/isolamento & purificação , Animais , Simulação por Computador , Humanos , Ipeca/química , Estrutura Molecular , Xenopus laevis
4.
J Ethnopharmacol ; 142(3): 762-8, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22683904

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Like many traditional medical systems found at Latin America, the very existence of a Brazilian traditional medical system is debated. Despite the absence of written material and organized knowledge, there is little doubt that Brazilians from all regions and all social classes recognize and access an estimated 4000 plant species with alleged therapeutic purposes as well as medicinal practices ranging from bone setting to spiritual healing. This "Brazilian folk medicine" is usually described as a rich mixture of African, European, and Indigenous medical traditions. AIM OF THE STUDY: This study questions this view, and argues it is both simplistic and Eurocentric. MATERIALS AND METHODS: By scrutinizing the origins of the medical uses of Zingiberis officinale, Curcuma longa, Ruta officinalis, Cephaelis ipecacuanha, Pilocarpus pinnatifolius, and curare (Chondrodendron, Abuta and Curarea), we illustrate the intense circulation of materials during imperial times. We further discuss how these practices articulated with local medical knowledge, and exemplify some of the ways by which knowledge was produced, transformed, incorporated, and resignified over time. DISCUSSION: Though not a systematic or comprehensive analysis of Brazilian folk medicine development, these selected examples show that, in opposition to usual simplistic descriptions, complex and convoluted manners of medicinal plant development occurred over time to compound both the Brazilian and European pharmaceutical armamentarium.


Assuntos
Disseminação de Informação , Medicina Tradicional , Plantas Medicinais , Brasil , Cephaelis , Curare , Curcuma , Etnofarmacologia , Gengibre , Humanos , Pilocarpus , Portugal , Ruta
5.
J Ethnopharmacol ; 138(3): 756-61, 2011 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-22041104

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Several roots or rhizomes of rubiaceous species are reportedly used as the emetic and antiamoebic drug ipecac. True ipecac (Carapichea ipecacuanha) is chemically well characterized, in contrast to striated or false ipecac derived from the rhizomes of Ronabea emetica (syn. Psychotria emetica). Besides its previous use as substitute of ipecac, the latter species is applied in traditional medicine of Panama and fruits of its relative Ronabea latifolia are reported as curare additives from Colombia. MATERIALS AND METHODS: Compounds of Ronabea emetica were isolated using standard chromatographic techniques, and structurally characterized by NMR spectroscopy and mass spectrometry. Organ specific distribution in Ronabea emetica as well as in Ronabea latifolia was further assessed by comparative HPLC analysis. RESULTS: Four iridoid-glucosides, asperuloside (1), 6α-hydroxygeniposide (2), deacetylasperulosidic acid (3) and asperulosidic acid (4) were extracted from leaves of Ronabea emetica. Rhizomes, used in traditional medicine, were dominated by 3. HPLC profiles of Ronabea latifolia were largely corresponding. These results contrast to the general tendency of producing emetine-type and indole alkaloids in species of Psychotria and closely related genera and merit chemotaxonomic significance, characterizing the newly delimited genus Ronabea. CONCLUSIONS: The aim of the work was to resolve the historic problem of adulteration of ipecac by establishing the chemical profile of Ronabea emetica, the false ipecac, as one of its less known sources. The paper demonstrates that different sources of ipecac can be distinguished by their phytochemistry, thus contributing to identifying adulterations of true ipecac.


Assuntos
Antieméticos/análise , Cephaelis/química , Iridoides/análise , Extratos Vegetais/análise , Psychotria/química , Cromatografia Líquida de Alta Pressão , Contaminação de Medicamentos , Frutas/química , Espectroscopia de Ressonância Magnética , Folhas de Planta/química , Caules de Planta/química , Plantas Medicinais/química , Rizoma/química
6.
J Biol Chem ; 285(10): 7722-38, 2010 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-20061395

RESUMO

The medicinal plant Psychotria ipecacuanha produces ipecac alkaloids, a series of monoterpenoid-isoquinoline alkaloids such as emetine and cephaeline, whose biosynthesis derives from condensation of dopamine and secologanin. Here, we identified three cDNAs, IpeOMT1-IpeOMT3, encoding ipecac alkaloid O-methyltransferases (OMTs) from P. ipecacuanha. They were coordinately transcribed with the recently identified ipecac alkaloid beta-glucosidase Ipeglu1. Their amino acid sequences were closely related to each other and rather to the flavonoid OMTs than to the OMTs involved in benzylisoquinoline alkaloid biosynthesis. Characterization of the recombinant IpeOMT enzymes with integration of the enzymatic properties of the IpeGlu1 revealed that emetine biosynthesis branches off from N-deacetylisoipecoside through its 6-O-methylation by IpeOMT1, with a minor contribution by IpeOMT2, followed by deglucosylation by IpeGlu1. The 7-hydroxy group of the isoquinoline skeleton of the aglycon is methylated by IpeOMT3 prior to the formation of protoemetine that is condensed with a second dopamine molecule, followed by sequential O-methylations by IpeOMT2 and IpeOMT1 to form cephaeline and emetine, respectively. In addition to this central pathway of ipecac alkaloid biosynthesis, formation of all methyl derivatives of ipecac alkaloids in P. ipecacuanha could be explained by the enzymatic activities of IpeOMT1-IpeOMT3, indicating that they are sufficient for all O-methylation reactions of ipecac alkaloid biosynthesis.


Assuntos
Cephaelis , Eméticos/metabolismo , Emetina/análogos & derivados , Emetina/biossíntese , Isoenzimas/metabolismo , Metiltransferases/metabolismo , Cephaelis/anatomia & histologia , Cephaelis/química , Cephaelis/enzimologia , Cromatografia Líquida , Eméticos/química , Emetina/química , Isoenzimas/classificação , Isoenzimas/genética , Metilação , Metiltransferases/classificação , Metiltransferases/genética , Dados de Sequência Molecular , Estrutura Molecular , Filogenia , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Espectrometria de Massas em Tandem
7.
Genetica ; 136(1): 57-67, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-18679809

RESUMO

Ipecac (Psychotria ipecacuanha) is a perennial, medicinal herb that grows in the understory of semi-deciduous tropical forests in the Neotropics. Ipecacs present a widely disjunct distribution, with two of its three ranges occurring in Brazil. The Amazonian populations are at least 1600 km from the nearest Atlantic populations. This work used ISSR markers to compare the genetic diversity and structure of populations from the two Brazilian ranges. Lower genetic diversity in Amazon populations (P = 60.11%, Hs = 0.18) and higher genetic diversity in Atlantic populations (P = 73.94%, Hs = 0.20) were detected. Differentiation between ranges were high (theta (B) = 0.6838, G(ST)-B = 0.6665). AMOVA revealed that 65.3% of the total molecular variance can be attributed to regional differences between the two ranges. Principal coordinate analyses and cluster analyses organized ipecacs at either individual or population level into two exclusive groups that correspond each to one of the two disjunct ranges, without exception. The results do not support a scenario that postulates human-mediated, long-distance dispersal events as a plausible origin for the distribution of the Brazilian ipecacs, but indicate geographic isolation as a long-standing barrier to genetic exchange and connectivity among populations from different ranges. Conservation implications are discussed.


Assuntos
Cephaelis/genética , Variação Genética , Conservação dos Recursos Naturais , DNA de Plantas/química , Evolução Molecular , Genética Populacional , Geografia , Filogenia
8.
J Biol Chem ; 283(50): 34650-9, 2008 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-18927081

RESUMO

Ipecac alkaloids produced in the medicinal plant Psychotria ipecacuanha such as emetine and cephaeline possess a monoterpenoid-tetrahydroisoquinoline skeleton, which is formed by condensation of dopamine and secologanin. Deglucosylation of one of the condensed products N-deacetylisoipecoside (1 alpha(S)-epimer) is considered to be a part of the reactions for emetine biosynthesis, whereas its 1 beta(R)-epimer N-deacetylipecoside is converted to ipecoside in P. ipecacuanha. Here, we isolated a cDNA clone Ipeglu1 encoding Ipecac alkaloid beta-D-glucosidase from P. ipecacuanha. The deduced protein showed 54 and 48% identities to raucaffricine beta-glucosidase and strictosidine beta-glucosidase, respectively. Recombinant IpeGlu1 enzyme preferentially hydrolyzed glucosidic Ipecac alkaloids except for their lactams, but showed poor or no activity toward other substrates, including terpenoid-indole alkaloid glucosides. Liquid chromatography-tandem mass spectrometry analysis of deglucosylated products of N-deacetylisoipecoside revealed spontaneous transitions of the highly reactive aglycons, one of which was supposed to be the intermediate for emetine biosynthesis. IpeGlu1 activity was extremely poor toward 7-O-methyl and 6,7-O,O-dimethyl derivatives. However, 6-O-methyl derivatives were hydrolyzed as efficiently as non-methylated substrates, suggesting the possibility of 6-O-methylation prior to deglucosylation by IpeGlu1. In contrast to the strictosidine beta-glucosidase that stereospecifically hydrolyzes 3 alpha(S)-epimer in terpenoid-indole alkaloid biosynthesis, IpeGlu1 lacked stereospecificity for its substrates where 1 beta(R)-epimers were preferred to 1 alpha(S)-epimers, although ipecoside (1 beta(R)) is a major alkaloidal glucoside in P. ipecacuanha, suggesting the compartmentalization of IpeGlu1 from ipecoside. These facts have significant implications for distinct physiological roles of 1 alpha(S)- and 1 beta(R)-epimers and for the involvement of IpeGlu1 in the metabolic fate of both of them.


Assuntos
Alcaloides/química , Cephaelis/enzimologia , Isoquinolinas/química , Terpenos/química , beta-Glucosidase/química , Bioquímica/métodos , Cephaelis/metabolismo , DNA Complementar/metabolismo , Escherichia coli/metabolismo , Cinética , Modelos Químicos , Dados de Sequência Molecular , Filogenia , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Especificidade por Substrato
9.
Planta Med ; 73(13): 1389-96, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17912675

RESUMO

Cytotoxic and apoptosis-inducing effects of the alkaloid emetine from Psychotria ipecacuanha (Rubiaceae) were studied in human cell lines. In Jurkat T-cells emetine leads to phosphatidylserine exposure, mitochondrial depolarisation, and DNA fragmentation. Furthermore, activation of several caspases (caspase-3, -9/6, and -8) was demonstrated in a fluorescent caspase assay. Bcl-2 over-expressing cells are less sensitive to emetine while caspase-8-deficient Jurkat T-cells react similarly to wild-type cells. This indicates that apoptosis induction is mediated via the mitochondrial pathway. By using hepatoma cell lines with differing p53 expression, it was concluded that p53 does not seem to play a role in apoptosis induction by emetine. Alterations of protein profiles during emetine-induced apoptosis were analysed by 2D-PAGE and MALDI-TOF-MS. A new protein spot was apparent after treatment with emetine: It could be identified as the N-terminal fragment lamin B1, which is released after cleavage by caspase-6.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Cephaelis , Emetina/farmacologia , Fitoterapia , Alcaloides/administração & dosagem , Alcaloides/farmacologia , Alcaloides/uso terapêutico , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/uso terapêutico , Relação Dose-Resposta a Droga , Emetina/administração & dosagem , Emetina/uso terapêutico , Citometria de Fluxo , Humanos , Células Jurkat/efeitos dos fármacos
10.
Braz J Biol ; 66(1A): 151-9, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16680318

RESUMO

Reproductive studies were carried out on Brazilian accessions of ipecac, Cephaelis ipecacuanha. Meiotic behavior was studied using the squashing technique. Irregular chromosome segregation in meiosis I and II, many sets of chromosomes in telophase II, micronuclei, incorrect cytoplasm division, incomplete cytokinesis and anomalous post-meiotic products, mainly polyads, were observed. The mean meiotic index was lower than 72%. Pollen viability was analyzed using Alexander solution, and the percentages ranged between brevistylous and longistylous floral morphs (85.3 to 93.1%), and among different localities (82.5 to 92.6%) analyzed. The size of pollen ranged between viable and sterile, and empty and shrunken sterile. In its natural habitat, this species is known to propagate by vegetative multiplication, but sexual reproduction seems to be as important as the vegetative propagation to this species.


Assuntos
Cephaelis/fisiologia , Segregação de Cromossomos/genética , Cromossomos de Plantas/genética , Meiose/fisiologia , Pólen/anatomia & histologia , Meiose/genética , Reprodução/genética , Reprodução/fisiologia
11.
Braz. j. biol ; 66(1a): 151-159, Feb. 2006. ilus, tab, graf
Artigo em Inglês | LILACS | ID: lil-426277

RESUMO

Estudos reprodutivos foram realizados em acessos brasileiros de poaia, Cephaelis ipecacuanha. O comportamento meiótico foi estudado usando a técnica de esmagamento. Foi observada segregação irregular de cromossomos durante meiose I e II, muitos grupos de cromossomos em telófase II, micronúcleos, divisão incorreta do citoplasma, citocinese incompleta e produtos pós-meióticos anômalos, principalmente políades. A média do índice meiótico foi inferior a 72%. A viabilidade polínica foi analisada utilizando-se solução de Alexander e a percentagem de pólen viável variou entre as formas florais, brevistila e longistila (85,3% a 93,1%), e entre as diferentes localidades (82,5% a 92,6%) analisadas. O tamanho do pólen variou entre viáveis e inviáveis, e entre os inviáveis vazios e contraídos. Em seu habitat natural, a poaia apresenta propagação por multiplicação vegetativa, mas a reprodução sexuada parece ser tão importante para essa espécie quanto a propagação vegetativa.


Assuntos
Cephaelis/fisiologia , Segregação de Cromossomos/genética , Cromossomos de Plantas/genética , Meiose/fisiologia , Pólen/anatomia & histologia , Meiose/genética , Reprodução/genética , Reprodução/fisiologia
12.
Planta Med ; 69(11): 1018-23, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14735440

RESUMO

Transformed root cultures of ipecac (Cephaelis ipecacuanha A. Richard), one of the recalcitrant woody plant species for Agrobacterium-mediated transformation, were established by co-culturing of in vitro petiole segments with Agrobacterium rhizogenes ATCC 15 834. Southern blot analysis of the established roots revealed that only the TL-DNA was integrated into the plant genome without incorporation of the TR-DNA. The transformed roots grew slowly on phytohormone-free solid medium and adventitious shoots were regenerated after over 6 months of culture on HF, half-strength Murashige and Skoog (1/2 MS) medium in the dark. The individually separated transformed shoots developed into plantlets on phytohormone-free solid medium at 25 degrees C under 16 h/day light, and the plants demonstrated wider leaves, shorter internodes and vigorous root growth compared to non-transformed plants. Effects of basal media and auxins on the growth and the ipecac alkaloid production of the transformed roots were investigated either under light or in the dark. The roots cultured in the dark grew well in Gamborg B5 (B5) liquid medium containing 0.5 mg/L IBA and yielded 112 mg/L of cephaeline and 14 mg/L emetine after 8 weeks of culture.


Assuntos
Cephaelis/crescimento & desenvolvimento , Cephaelis/genética , Fitoterapia , Rhizobium/fisiologia , Transformação Genética , Southern Blotting , Cephaelis/microbiologia , Expressão Gênica , Humanos , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Brotos de Planta/microbiologia , Brotos de Planta/fisiologia , Plantas Geneticamente Modificadas
13.
Phytochemistry ; 59(1): 91-7, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11754950

RESUMO

From the dried roots of Cephaelis acuminata, five tetrahydroisoquinoline-monoterpene glycosides, 2-O-beta-D-glucopyranosyldemethylalangiside, demethylisoalangiside, 6"-O-beta-D-glucopyranosylipecoside, 6"-O-alpha-D-glucopyranosylipecoside and (4R)-4-hydroxyipecoside, were isolated. The structures of these glycosides were determined by spectroscopic and chemical means.


Assuntos
Alcaloides/isolamento & purificação , Cephaelis/química , Glucosídeos/isolamento & purificação , Isoquinolinas/isolamento & purificação , Monoterpenos , Alcaloides/química , Eméticos/química , Eméticos/isolamento & purificação , Glucosídeos/química , Isoquinolinas/química , Raízes de Plantas/química
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