Publications by authors named "Celso Oliveira Rezende Junior"

Microorganisms can induce diseases with significant clinical implications for human health. Multidrug-resistant microorganisms have been on the rise worldwide over the past few decades, and no new antibiotics have been introduced to the market in a considerable amount of time. Such situation highlights the urgency of discovering new antimicrobial drugs to address this pressing issue.

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This study introduces further insights from the hit-to-lead optimization process involving a series of benzimidazole derivatives acting as inhibitors of the cruzain enzyme, which targets Trypanosoma cruzi, the causative parasite of Chagas disease. Here, we present the design, synthesis and biological evaluation of 30 new compounds as a third generation of benzimidazole analogues with trypanocidal activity, aiming to enhance our understanding of their pharmacokinetic profiles and establish a structure-metabolism relationships within the series. The design of these new analogues was guided by the analysis of previous pharmacokinetic results, considering identified metabolic sites and biotransformation studies.

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Introduction: Benznidazole, the drug of choice for treating Chagas Disease (CD), has significant limitations, such as poor cure efficacy, mainly in the chronic phase of CD, association with side effects, and parasite resistance. Understanding parasite resistance to benznidazole is crucial for developing new drugs to treat CD.

Areas Covered: Here, the authors review the current understanding of the molecular basis of benznidazole resistance.

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Leishmaniasis and Chagas disease are neglected tropical diseases caused by Trypanosomatidae parasites. Given the numerous limitations associated with current treatments, such as extended treatment duration, variable efficacy, and severe side effects, there is an urgent imperative to explore novel therapeutic options. This study details the early stages of hit-to-lead optimization for a benzenesulfonyl derivative, denoted as initial hit, against Trypanossoma cruzi (T.

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An early exploration of the benzothiazole class against two kinetoplastid parasites, Leishmania infantum and Trypanosoma cruzi, has been performed after the identification of a benzothiazole derivative as a suitable antileishmanial initial hit. The first series of derivatives focused on the acyl fragment of its class, evaluating diverse linear and cyclic, alkyl and aromatic substituents, and identified two other potent compounds, the phenyl and cyclohexyl derivatives. Subsequently, new compounds were designed to assess the impact of the presence of diverse substituents on the benzothiazole ring or the replacement of the endocyclic sulfur by other heteroatoms.

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Chagas disease is caused by the parasite , and the lack of effective and safe treatments makes identifying new classes of compounds with anti- activity of paramount importance. Hit-to-lead exploration of a metabolically stable -imidazoylpiperazine was performed. Compound , a piperazine derivative active against , was selected to perform the hit-to-lead exploration, which involved the design, synthesis and biological evaluation of 39 new derivatives.

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Zika virus infection is associated to severe diseases such as congenital microcephaly and Zika fever causing serious harm to humans and special concern to health systems in low-income countries. Currently, there are no approved drugs against the virus, and the development of anti-Zika virus drugs is thus urgent. The present investigation describes the discovery and hit expansion of a N-acyl-2-aminobenzothiazole series of compounds against Zika virus replication.

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Discovery of novel SARS-CoV-2 main protease (M) inhibitors using a structure-based drug discovery strategy. Virtual screening employing covalent and noncovalent docking was performed to discover M inhibitors, which were subsequently evaluated in biochemical and cellular assays. 91 virtual hits were selected for biochemical assays, and four were confirmed as reversible inhibitors of SARS CoV-2 M with IC values of 0.

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Chagas disease is a neglected tropical disease caused by Trypanosoma cruzi. Because current treatments present several limitations, including long duration, variable efficacy and serious side effects, there is an urgent need to explore new antitrypanosomal drugs. The present study describes the hit-to-lead optimization of a 2-aminobenzimidazole hit 1 identified through in vitro phenotypic screening of a chemical library against intracellular Trypanosoma cruzi amastigotes, which focused on optimizing potency, selectivity, microsomal stability and lipophilicity.

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Chagas disease is a neglected tropical disease, endemic in Latin America and caused by the protozoan parasite Trypanosoma cruzi. Available treatments show low cure efficacy during the chronic phase of the disease and cause a series of side effects, reinforcing the need to develop new drugs against Chagas disease. In this work, we describe the optimization of a trypanocidal hit compound recently reported in phenotypic high-throughput screening studies against Trypanosoma cruzi.

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Natural products based on imidazole scaffolds have inspired the discovery of a wide variety of bioactive compounds. Herein, a series of imidazoles that act as competitive and potent cruzain inhibitors was investigated using a combination of ligand- and structure-based drug design strategies. Quantitative structure-activity relationships (QSARs) were generated along with the investigation of enzyme-inhibitor molecular interactions.

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A virtual screening conducted with nearly 4 000 000 compounds from lead-like and fragment-like subsets enabled the identification of a small-molecule inhibitor () of the cruzain enzyme, a validated drug target for Chagas disease. Subsequent comprehensive structure-based drug design and structure-activity relationship studies led to the discovery of carbamoyl imidazoles as potent, reversible, and competitive cruzain inhibitors. The most potent carbamoyl imidazole inhibitor () exhibited high affinity with a value of 20 nM, presenting both and activity against .

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The studies culminating in the synthesis of two large subunits of tautomycetin are described. The first one, fragment C1-C12 that has an -1,3-dimethyl system and a terminal diene unit, was accomplished in 10 linear steps in 7.4% overall yield.

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Four diamines and three amino alcohols derived from 1-decanol, 1-dodecanol and 1,2-dodecanediol were evaluated in an in vitro assay against a mixture of trypomastigote and intracellular amastigote forms of Trypanosoma cruzi. Two of these compounds (6 and 7) showed better activity against both proliferative stages of T. cruzi than the positive control benznidazole, three were of similar potency (1, 2 and 5) and two were less active (3 and 4).

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