Publications by authors named "Claudio Viegas Junior"

Article Synopsis
  • * Researchers utilized a ligand-fishing technique with immobilized 3CL protease on magnetic beads, which allowed them to identify and isolate active peptides that further enhanced inhibition to 82.7%.
  • * Molecular simulations and additional testing revealed that four out of seven identified peptides were effective at inhibiting the 3CL protease, indicating the potential of these seaweed-derived peptides as antiviral agents against COVID-19.
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Background: Garcinia brasiliensis is a species native to the Amazon forest. The white mucilaginous pulp is used in folk medicine as a wound healing agent and for peptic ulcer, urinary, and tumor disease treatments. The activity of the proprotein convertases (PCs) Subtilisin/Kex is associated with the development of viral, bacterial and fungal infections, osteoporosis, hyperglycemia, atherosclerosis, cardiovascular, neurodegenerative and neoplastic diseases.

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Leishmaniasis is one of the most important neglected tropical diseases (NTDs) that are especially common among low-income populations in developing regions of Africa, Asia, and the Americas. Many natural products, particularly alkaloids, have been reported to have inhibitory activity against arginase, the key enzyme in the pathology caused by Leishmania sp. In this way, piperidine alkaloids (-)-cassine (1), (-)-spectaline (2), (-)-3-O-acetylcassine (3), and (-)-3-O-acetylspectaline (4) were isolated from Senna spectabilis flowers.

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Rationale: Piperidine alkaloids from Senna spectabilis constitute a rare class of natural products with several biological activities. However, the absence of chromophores makes their structural elucidation by conventional methods a great challenge. In this context, mass spectrometry emerges as a powerful tool for metabolomics studies.

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Cancer is one of the most critical problems of public health in the world and one of the main challenges for medicine in this century. Unfortunately, most patients are diagnosed at advanced stage, when the treatment options are palliative. Consequently, the search for novel therapeutic options is imperative.

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The leishmanicidal potential of benzophenones has been described, some of them highlighting their potential as cysteine protease inhibitors. Therefore, this work described leishmanicidal activity of nine benzophenone derivatives (1a-c;2a-c;3a-c) against intramacrophage amastigote forms of Leishmania(L.)amazonensis (IC50) and the cytotoxic effect on murine peritoneal macrophages (CC50).

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The natural biflavonoids morelloflavone-4‴-O-β-D-glycosyl (1), (±)-fukugiside (2) and morelloflavone (3) were isolated from the ethyl acetate extract (EAEE) of dried and powdered fruit epicarps of Garcinia brasiliensis and derivatives of morelloflavone were semi-synthesised. Morelloflavone-7,4',7″,3‴,4‴-penta-O-acetyl (4), morelloflavone-7,4',7″,3‴,4‴-penta-O-methyl (5) and morelloflavone-7,4',7″,3‴,4‴-penta-O-butanoyl (6) were prepared by acylation and alkylation reactions. All compounds showed leishmanicidal, antiproteolytic and antioxidant activities in addition to exhibiting low cytotoxicity.

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Molecular hybridization is a new concept in drug design and development based on the combination of pharmacophoric moieties of different bioactive substances to produce a new hybrid compound with improved affinity and efficacy, when compared to the parent drugs. Additionally, this strategy can result in compounds presenting modified selectivity profile, different and/or dual modes of action and reduced undesired side effects. So, in this paper, we described several examples of different strategies for drug design, discovery and pharmacomodulation focused on new innovative hybrid compounds presenting analgesic, anti-inflammatory, platelet anti-aggregating, anti-infectious, anticancer, cardio- and neuroactive properties.

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