Synthesis and activity of novel tetrazole compounds and their pyrazole-4-carbonitrile precursors against Leishmania spp.

A new series of 5-(1-aryl-3-methyl-1H-pyrazol-4-yl)-1H-tetrazole derivatives (4a-m) and their precursor 1-aryl-3-methyl-1H-pyrazole-4-carbonitriles (3a-m) were synthesized and evaluated as antileishmanials against Leishmania braziliensis and Leishmania amazonensis promastigotes in vitro. In parallel, the cytotoxicity of these compounds was evaluated on the RAW 264.7 cell line.

Chemical and biological analyses of the essential oils and main constituents of Piper species.

The essential oils obtained from leaves of Piper duckei and Piper demeraranum by hydrodistillation were analyzed by gas chromatography-mass spectrometry. The main constituents found in P. demeraranum oil were limonene (19.

Anti-leishmanial activity of alkaloidal extracts obtained from different organs of Aspidosperma ramiflorum.

The present study was designated to evaluate semi-quantitative antileishmanial activity of alkaloidal extracts that were obtained from 1g of different parts of Aspidosperma ramiflorum (leaves, roots, seeds, and stem barks). Alkaloidal extracts of barks and leaves presented a good activity against the extracellular form (promastigotes) of Leishmania (L.) amazonensis.

Evaluation of thiosemicarbazones and semicarbazones as potential agents anti-Trypanosoma cruzi.

Synthetic thiosemicarbazones and semicarbazones were evaluated for their Trypanosoma cruzi trypomastigotes obtained from LLC-MK2 cell cultures. In general, thiosemicarbazone derivatives were most effective and among them the 4-N-(2'-methoxy styryl)-thiosemicarbazone was chosen, to compare the in vitro effect against amastigotes of T. cruzi lodged in mouse peritoneal and human macrophages.

Differences in the antigenic profile and infectivity of murine macrophages of Leishmania (Viannia) parasites.

The antigenic profile and infectivity were compared between 3 recent Leishmania (Viannia) isolates from the Amazonian region (Instituto Nacional de Pesquisas da Amazonia [INPA] strains) and 3 World Health Organization (WHO) reference species (Leishmania guyanensis, Leishmania braziliensis, and Leishmania naiffi). Differences were observed in the peak and extent of promastigote growth. The WHO reference strains exhibited significantly higher exponential growth as promastigotes than INPA strains.

Activity of Brazilian and Bulgarian propolis against different species of Leishmania.

Extracts of propolis samples collected in Brazil and Bulgaria were assayed against four Leishmania species--Leishmania amazonensis, L. braziliensis, L. chagasi from the New World, and L.

Nitric oxide biosynthesis by Leishmania amazonensis promastigotes containing a high percentage of metacyclic forms.

Due to the diversity of its physiological and pathophysiological functions and general ubiquity, the study of nitric oxide (NO) has become of great interest. In this work, it was demonstrated that Leishmania amazonensis promastigotes produces NO, a free radical synthesized from L: -arginine by nitric oxide synthase (NOS). A soluble NOS was purified from L.

A pyrimidine-beta-carboline and other alkaloids from Annona foetida with antileishmanial activity.

Bioassay-guided fractionation of the bark extract of Annona foetida afforded a new antileishmanial pyrimidine-beta-carboline alkaloid, N-hydroxyannomontine (1), together with the previously reported annomontine (2), O-methylmoschatoline (3), and liriodenine (4). The structure of compound 1 was established on the basis of extensive 1D and 2D NMR and MS analyses. This is the third reported pyrimidine-beta-carboline-type alkaloid and is particularly important for Annona genus chemotaxonomy.

Synthesis and leishmanicidal activities of 1-(4-X-phenyl)-N'-[(4-Y-phenyl)methylene]-1H-pyrazole-4-carbohydrazides.

1H-pyrazole-4-carbohydrazides were synthesized and their leishmanicidal in vitro activities and cytotoxic effects were investigated. The drugs prototypes of these new compounds (ketoconazole, benznidazole, allopurinol and pentamidine) were also tested. It was found that among all the 1H-pyrazole-4-carbohydrazides derivatives examined, the most active compounds were those with X = Br, Y = NO2 (27) and X = NO2, Y = Cl (15) derivatives which showed to be most effective on promastigotes forms of L.

Antileishmanial activity of lapachol analogues.

The antileishmanial activity of lapachol, isolapachol, and dihydrolapachol, along with soluble derivatives (potassium salt) and acetate was obtained. All the compounds were assayed against metacyclic promastigotes of two different species of Leishmania associated to tegumentar leishmaniasis: L. amazonensis and L.

Anti-leishmanial activity of alkaloidal extract from Aspidosperma ramiflorum.

Infections due to protozoa of the genus Leishmania are a major worldwide health problem, with high endemicity in developing countries. The drugs of choice for the treatment of leishmaniasis are the pentavalent antimonials (SbV), which present renal and cardiac toxicity. Besides, the precise chemical structure and mechanism of action of these drugs are unknown up to date.

3-[4'-bromo-(1,1'-biphenyl)-4-yl]-N, N-dimethyl-3-(2-thienyl)-2-propen-1-amine: synthesis, cytotoxicity, and leishmanicidal, trypanocidal and antimycobacterial activities.

Current therapies for Chagas' disease, leishmaniasis and tuberculosis are unsatisfactory because of the failure rates, significant toxicity and/or drug resistance. In this study, the compound 3-[4'-bromo-(1,1'-biphenyl)-4-yl]-N,N-dimethyl-3-(2-thienyl)-2-propen-1-amine (IV) was synthesized and its trypanocidal, leishmanicidal and antimycobacterial activities were investigated. The cytotoxicity was determined on V79 cells with three endpoints: nucleic acid content, 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide reduction and Neutral Red uptake.