Hit-to-lead optimization of novel 2-alkylaminomethylquinoline derivatives as anti-chagas agents.

Chagas disease is one of the main neglected diseases in the world, being endemic in 21 countries of Latin America. This disease has become a global health problem due to migration of infected people non-endemic countries. Even though this disease affects millions of people, only two drugs are approved for its treatment, benznidazole and nifurtimox, and both have several limitations.

gem-Diol and Hemiacetal Forms in Formylpyridine and Vitamin-B-Related Compounds: Solid-State NMR and Single-Crystal X-ray Diffraction Studies.

The gem-diol moieties of organic compounds are rarely isolated or even studied in the solid state. Here, liquid- and solid-state NMR, together with single-crystal X-ray diffraction studies, were used to show different strategies to favor the gem-diol or carbonyl moieties and to isolate hemiacetal structures in formylpyridine and vitamin-B-related compounds. The change in position of the carbonyl group in pyridine compounds had a clear and direct effect on the hydration, which was enhanced by trifluoroacetic acid addition.

Microwave-assisted Synthesis of 2-Styrylquinoline-4-carboxylic Acids as Antitubercular Agents.

Background: Many 2-substituted quinolines and especially 2-arylvinyl derivatives isolated from plants or prepared by synthesis have been designed from ethnopharmacological studies.

Objective: In order to explore new aspects of the structure-antituberculosis activity relationship, a series of styrylquinoline derivatives was prepared.

Method: A series of styrylquinoline derivatives was prepared from quinaldic acid and a variety of arylbenzaldehydes under eco-friendly conditions via Knoevenagel reaction and trifluoroacetic acid (TFA) as catalyst.

HmuS and HmuQ of Ensifer/Sinorhizobium meliloti degrade heme in vitro and participate in heme metabolism in vivo.

Ensifer meliloti is a nitrogen-fixing symbiont of the alfalfa legume able to use heme as an iron source. The transport mechanism involved in heme acquisition in E. meliloti has been identified and characterized, but the fate of heme once inside the cell is not known.

Synthesis and evaluation of 2-(1H-indol-3-yl)-4-phenylquinolines as inhibitors of cholesterol esterase.

A series of 2-(substituted) phenyl and 2-indolyl quinoline derivatives (10a-l) was synthesized by an efficient microwave-assisted, trifluoroacetic acid-catalyzed, solvent-free method. Evaluation of the inhibitory activity led to the identification of two quinoline inhibitors of cholesterol esterase. 2-(1H-Indol-3-yl)-6-nitro-4-phenylquinoline (10l; IC50=1.

Design, synthesis and evaluation of acridine and fused-quinoline derivatives as potential anti-tuberculosis agents.

The synthesis of twelve acridine and polycyclic acridine derivatives prepared via the Friedländer reaction is described. The one-pot reactions of 2-amino-5-chloro or 5-nitro-benzophenones and a variety of cyclanones and indanones were carried out in a MW oven under TFA catalysis in good yields. The products were designed according natural antituberculosis products and were evaluated for growth inhibitory activity towards Mycobacterium tuberculosis H37Rv (Mtb) through the National Institute of Allergy and Infectious Diseases (NIAID, USA).

Synthesis, trypanocidal activity and molecular modeling studies of 2-alkylaminomethylquinoline derivatives.

Research and development of new drugs effective in the treatment of Trypanosoma cruzi infections are a real need for the 16 million people infected in the Americas. In a previous work, a quinoline derivative substituted by a 2-piperidylmethyl moiety showed to be active against Chagas disease and was considered a lead compound for further optimization. A series of ten analogous derivatives were tested against epimastigotes as a first approach.

NMR characterization of hydrate and aldehyde forms of imidazole-2-carboxaldehyde and derivatives.

The existence and stability of the aldehyde-hydrate form of imidazole-2-carboxaldehyde (4) were studied using FTIR together with solution- and solid-state NMR experiments. The results allowed us to conclude that the hydrate form was stable and precipitated at pH = 8.0 and that the aldehyde form was isolated at pH = 6.

Isoporphyrin intermediate in heme oxygenase catalysis. Oxidation of alpha-meso-phenylheme.

Human heme oxygenase-1 (hHO-1) catalyzes the O2- and NADPH-dependent oxidation of heme to biliverdin, CO, and free iron. The first step involves regiospecific insertion of an oxygen atom at the alpha-meso carbon by a ferric hydroperoxide and is predicted to proceed via an isoporphyrin pi-cation intermediate. Here we report spectroscopic detection of a transient intermediate during oxidation by hHO-1 of alpha-meso-phenylheme-IX, alpha-meso-(p-methylphenyl)-mesoheme-III, and alpha-meso-(p-trifluoromethylphenyl)-mesoheme-III.

Human heme oxygenase oxidation of 5- and 15-phenylhemes.

Human heme oxygenase-1 (hHO-1) catalyzes the O2-dependent oxidation of heme to biliverdin, CO, and free iron. Previous work indicated that electrophilic addition of the terminal oxygen of the ferric hydroperoxo complex to the alpha-meso-carbon gives 5-hydroxyheme. Earlier efforts to block this reaction with a 5-methyl substituent failed, as the reaction still gave biliverdin IXalpha.