Publications (47) View all
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Article: Convolutamydine A and synthetic analogues have antinociceptive properties in mice.
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ABSTRACT: Convolutamydine A, an oxindole that originated from a marine bryozoan, has several biological effects. In this study, we aimed to investigate the antinociceptive effects of convolutamydine A and two new synthetic analogues. Convolutamydine A and the two analogues were given orally to assess their ability to induce antinociceptive effects. Formalin-induced licking response, acetic acid-induced contortions, and hot plate models were used to characterize the effects of convolutamydine A and its analogues. Convolutamydine A (4,6-bromo-3-(2-oxopropyl)-3-hydroxy-2-oxindole), compound 1 (3-(2-oxopropyl)-3-hydroxy-2-oxindole), and compound 2 (5-bromo-3-(2-oxopropyl)-3-hydroxy-2-oxindole) caused peripheral antinociceptive and anti-inflammatory effects in the acetic acid-induced contortions and the formalin-induced licking models. Supraspinal effects were also observed in the hot plate model and were similar to those obtained with morphine. The peripheral effects were not mediated by the cholinergic or opioid systems. The antinociceptive effects of convolutamydine A seem to be mediated by all three systems (cholinergic, opioid, and nitric oxide systems), and the mechanism of action of compounds 1 and 2 involved cholinergic and nitric oxide-mediated mechanisms. Convolutamydine A and its analogues (compounds 1 and 2) showed good antinociceptive ability after systemic administration in acute pain models. The antinociceptive action mediated by cholinergic, opioid, and nitric oxide systems could explain why convolutamydine A, 1, and 2 retained their antinociceptive effects. The doses used were similar to the doses of morphine and were much lower than those of acetylsalicylic acid, the classical analgesic and anti-inflammatory drug. In conclusion, convolutamydine A and the two analogues demonstrated antinociceptive effects comparable to morphine's effects.Pharmacology Biochemistry and Behavior 10/2012; · 2.53 Impact Factor -
Article: Anthraquinones from the bark of Senna macranthera.
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ABSTRACT: 2-acetyl physcion (2-acetyl-1,8-dihydroxy-6-methoxy-3-methyl-9,10-anthraquinone, 2), a rare anthraquinone, was isolated from Senna macranthera var. nervosa (Vogel) H.S. Irwin & Barneby (Fabaceae). The chemical structure was elucidated and all (1)H and (13)C NMR chemical shifts were assigned by NMR one- ((1)HNMR, {(1)H}-(13)CNMR, and APT-(13)CNMR) and two (COSY, NOESY, HMQC and HMBC) dimensional of this natural compound. Furthermore, the minor anthraquinones chrysophanol (3), chrysophanol-8-methyl ether (4) and physcion (5) were characterized by GC-MS analysis. The occurrence of the anthraquinones 3-5 confirms that S. macranthera is a typical representative of the genus Senna.Anais da Academia Brasileira de Ciências 12/2011; 83(4):1159-64. · 1.09 Impact Factor -
Article: Novel 1,2,3-triazole derivatives for use against Mycobacterium tuberculosis H37Rv (ATCC 27294) strain.
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ABSTRACT: The purpose of this study was to prepare various 4-substituted N-phenyl-1,2,3-triazole derivatives using click chemistry. The derivatives were screened in vitro for antimicrobial activity against Mycobacterium tuberculosis strain H37Rv (ATCC 27294) using the Alamar Blue susceptibility test. The activity was expressed as the minimum inhibitory concentration (MIC) in μg/mL (μM). Derivatives of isoniazid (INH), (E)-N'-[(1-aryl)-1H-1,2,3-triazole-4-yl)methylene] isonicotinoyl hydrazides, exhibited significant activity with MIC values ranging from 2.5 to 0.62 μg/mL. In addition, they displayed low cytotoxicity against liver cells (hepatoma HepG2) and kidney cells (BGM), thereby providing a high therapeutic index. The results demonstrated the potential and importance of developing new INH derivatives to treat mycobacterial infections.Journal of Medicinal Chemistry 08/2011; 54(17):5988-99. · 4.80 Impact Factor -
Article: Synthesis and anti-Trypanosoma cruzi activity of β-lapachone analogues.
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ABSTRACT: The available chemotherapy for Chagas disease, caused by Trypanosoma cruzi, is unsatisfactory; therefore, there is an intense effort to find new drugs for the treatment of this disease. In our laboratory, we have analyzed the effect on bloodstream trypomastigotes of 16 new naphthoquinone analogues of β-lapachone modified in the pyran ring, aiming to find a new prototype with high trypanocidal activity. The new compounds presented a broad spectrum of activity, and five of them presented IC(50)/24 h in the range of 22-63 μM, whereas β-lapachone had a higher value of 391.5 ± 16.5 μM.European journal of medicinal chemistry 03/2011; 46(7):3071-7. · 3.27 Impact Factor -
Article: The mechanism of Sandmeyer's cyclization reaction by electrospray ionization mass spectrometry.
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ABSTRACT: Using electrospray ionization (tandem) mass spectrometry (ESI-MS(/MS)) spectrometric experiments, the Sandmeyer reaction was monitored on-line, and key intermediates were intercepted and characterized for the first time. The mechanistic information provided by on-line ESI-MS(/MS) is in accordance with Sandmeyer's proposal, and was made possible by coupling a microreactor on-line to the ESI ion source, which allowed reactions to be screened from 0.7-2.0 s, identifying and characterizing all intermediates that were formed and consumed during the reaction.Rapid Communications in Mass Spectrometry 02/2011; 25(3):423-8. · 2.79 Impact Factor
