40 research outputs found

    Estudo fitoquímico de espécimens cultivados de cumaru (Amburana cearensis A. C. Smith)

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    Due to the threat of extinction of Amburana cearensis, a tree of medicinal importance for the Northeastern Brazil, a phytochemical analysis was performed with specimens obtained by seed germination. Ten compounds were isolated and identified by spectroscopic methods and comparison with literature data. p-Hydroxybenzoic acid, ayapin, (E/Z)-melilotosides are being reported for the first time for the genus, besides coumarin, isokaempferide, vanillic acid, protocatechuic acid, amburosides A and B which have already been found in the trunk bark. Based on physical and NMR spectroscopy evidences the structures of several melilotosides already described in the literature have been suggested to be revised

    Flavonoides e sesquiterpenos de Croton pedicellatus Kunth

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    The chemical investigation of the ethanolic extract from leaves of Croton pedicellatus yielded the bis-nor-sesquiterpenes blumenol A and blumenol A glucoside, along with the flavonoids: tiliroside, 6"-O-p-coumaroyl-β-galactopyranosyl- kaempferol, 6"-O-p-coumaroyl-β-glucopyranosyl-3"-methoxy- kaempferol, kaempferol, 3-glucopyranosyl-quercetin and alpinumisoflavone, as well as 4-hydroxy-3,5-dimethoxybenzoic acid. The identification of all isolated compounds was performed by spectrometric methods, including HR-ESI-MS, 1D and 2D NMR experiments, and by comparison with previously-described physical and spectral data

    Chemical composition of aspidosperma ulei markgr. and antiplasmodial activity of selected indole alkaloids

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    A new indole alkaloid, 12-hydroxy-N-acetyl-21(N)-dehydroplumeran-18-oic acid (13), and 11 known indole alkaloids: 3,4,5,6-tetradehydro-β-yohimbine (3), 19(E)- hunteracine (4), β-yohimbine (5), yohimbine (6), 19,20-dehydro-17-α-yohimbine (7), uleine (10), 20-epi-dasycarpidone (11), olivacine (8), 20-epi-N-nor-dasycarpidone (14), N-demethyluleine (15) and 20(E)-nor-subincanadine E (12) and a boonein △-lactone 9, ursolic acid (1) and 1D,1O-methyl-chiro-inositol (2) were isolated from the EtOH extracts of different parts of Aspidosperma ulei Markgr. (Apocynaceae). Identification and structural elucidation were based on IR, MS, 1H- and 13C-NMR spectral data and comparison to literature data. The antiplasmodial and antimalarial activity of 1, 5, 6, 8, 10 and 15 has been previously evaluated and 1 and 10 have important in vitro and in vivo antimalarial properties according to patent and/or scientific literature. With the aim of discovering new antiplasmodial indole alkaloids, 3, 4, 11, 12 and 13 were evaluated for in vitro inhibition against the multi-drug resistant K1 strain of the human malaria parasite Plasmodium falciparum. IC50 values of 14.0 (39.9), 4.5 (16.7) and 14.5 (54.3) μg/mL (μM) were determined for 3, 11 and 12, respectively. Inhibitory activity of 3, 4, 11, 12 and 13 was evaluated against NIH3T3 murine fibroblasts. None of these compounds exhibited toxicity to fibroblasts (IC50 > 50 μg/mL). Of the five compounds screened for in vitro antiplasmodial activity, only 11 was active. © 2013 by the authors

    Cytotoxic lipidic α-amino acids from the zoanthid Protopalythoa variabilis from the Northeastern coast of Brazil

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    Two lipidic α-amino acids 1a and 1b were isolated from the zoanthid Protopalythoa variabilis using a bioguided fractionation for cytotoxic activity. The structures of the metabolites were determined by spectroscopic methods, including NMR (nuclear magnetic resonance) ¹H e 13C, IR (infrared) and high resolution mass spectrometry (positive mode). The cytotoxic activity of the crude extract, as well as of the mixture of 1a and 1b were measured in vitro using the MTT assay for four human tumor cell lines. This finding has important biological and chemical implications for this type of compound. This is the first report of lipidic α-amino acids from natural sources, as well as of their cytotoxic activity.Dois α-aminoácidos lipídicos 1a e 1b foram isolados do zoantídeo Protopalythoa variabilis através de fracionamento guiado pela atividade citotóxica. As estruturas foram determinadas por diferentes métodos espectroscópicos, tais como, RMN (ressonância magnética nuclear) ¹H e 13C, IV (infravermelho) e espectrometria de massa de alta resolução (modo positivo). A atividade citotóxica dos extratos, das frações e 1a/1b foi avaliada in vitro através do teste do MTT contra quatro linhagens de células tumorais. Este achado tem implicações biológicas e químicas importantes para essa classe de compostos. Este é o primeiro relato de α-aminoácidos lipídicos a partir de uma fonte natural, bem como de sua atividade citotóxica.CNPqFINEPInstitute Claude Bernar

    Structure Elucidation and Anticancer Activity of 7-Oxostaurosporine Derivatives from the Brazilian Endemic Tunicate Eudistoma vannamei

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    The present study reports the identification of two new staurosporine derivatives, 2-hydroxy-7-oxostaurosporine (1) and 3-hydroxy-7-oxostaurosporine (2), obtained from mid-polar fractions of an aqueous methanol extract of the tunicate Eudistoma vannamei, endemic to the northeast coast of Brazil. The mixture of 1 and 2 displayed IC50 values in the nM range and was up to 14 times more cytotoxic than staurosporine across a panel of tumor cell lines, as evaluated using the MTT assay.CNPqCAPESInCBFAPES

    Constituintes químicos dos frutos de Copaifera langsdorffii Desf.

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    Phytochemical investigation of the hexane extract of fruit shells of Copaifera langsdorffii Desf. (Caesalpinioideae) afforded ent-kaur-16-en-19-oic acid, polyalthic acid, nivenolide and the mixture of caryophyllene oxide and ent-kaur-16-en-19-oic acid. The chloroform extract of unripe seeds led to the isolation of coumarin and the GC/MS analysis of the extract allowed the identification of 81.8% of the fatty acid composition after hydrolysis followed by methylation. The main fatty acid identified was oleic acid (33.1%). The isolation of all secondary metabolites was accomplished by modern chromatographic methods and the structure determination was accomplished by spectrometric methods (IR, MS, NMR ¹H and 13C)

    Efeitos de óleos essenciais de plantas no tempo de sono induzido por cetamina em camundongos

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    Estudos anteriores mostraram que óleos essenciais voláteis obtidos de plantas potenciam o tempo de sono induzido por pentobarbital e álcool em camundongos. Cetamina é um anestésico muito utilizado em crianças, sendo conhecida por causar uma anestesia dissociativa. Seus efeitos alucinógenos podem ser reduzidos quando administrada em associação a benzodiazepínicos. O objetivo deste estudo foi determinar a influência dos óleos de Psidium guyanensis (Araçá azedo), Psidium pohlianum (Araçá doce), Psidium guajava (Araçá goiaba), Rosmarinus officinalis (Alecrim) e Lippia alba (Cidreira) no tempo de sono induzido por cetamina em camundongos. Os resultados indicam que o tempo de sono induzido por cetamina foi prolongado pelos óleos essenciais de Psidium guyanensis, Psidium pohlianum, Psidium guajava e Lippia Alba mostrando novas possibilidades de associação com a cetamina a fim de prolongar o seu efeito sedativo, proporcionando uma anestesia mais adequada
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