Navegando por Autor "Silveira, Benila Maria"

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    Brazilian essential oils as source for the discovery of new anti-COVID-19 drug : a review guided by in silico study.
    (2021) Amparo, Tatiane Roquete; Seibert, Janaína Brandão; Silveira, Benila Maria; Costa, Fernanda Senna Ferreira; Almeida, Tamires Cunha; Braga, Saulo Fehelberg Pinto; Silva, Glenda Nicioli da; Santos, Orlando David Henrique dos; Souza, Gustavo Henrique Bianco de
    The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in China and its spread worldwide has become one of the biggest health problem due to the lack of knowledge about an effective chemotherapy. Based on the current reality of the SARS-CoV-2 pandemic, this study aimed to make a review literature about potential anti-coronavirus natural compounds guided by an in silico study. In the first step, essential oils from native species found in the Brazilian herbal medicine market and Brazilian species that have already shown antiviral potential were used as source for the literature search and compounds selection. Among these compounds, 184 showed high antiviral potential against rhinovirus or picornavirus by quantitative structure–activity relationship analysis. (E)-a-atlantone; 14-hydroxy-amuurolene; allo-aromadendrene epoxide; amorpha4,9-dien-2-ol; aristochene; azulenol; germacrene A; guaia-6,9-diene; hedycaryol; humulene epoxide II; aamorphene; a-cadinene; a-calacorene and a-muurolene showed by a molecular docking study the best result for four target proteins that are essential for SARS-CoV-2 lifecycle. In addition, other parameters obtained for the selected compounds indicated low toxicity and showed good probability to achieve cell permeability and be used as a drug. These results guided the second literature search which included other species in addition to native Brazilian plants. The majority presence of any of these compounds was reported for essential oils from 45 species. In view of the few studies relating essential oils and antiviral activity, this review is important for future assays against the new coronavirus.
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    Chemistry modification of PMMA-g-PEG copolymer.
    (2014) Rosa, Juliana dos Santos; Silveira, Benila Maria; Novack, Kátia Monteiro; Santos, Viviane Martins Rebello dos; Teixeira, Leonardo César de Moraes
    Copolymers are polymers consisting of different repeat units and their production is usually motivated by the changing of polymers properties. An important application are the transportation of drugs within the organism with the aim of controlling the release of the substance. The synthesis of these new copolymers is based on simple semi-synthesis and low cost. The synthetic routes are based on the interaction of the graft copolymer (PMMA-g-PEG) with a variety of reagents such as acetic anhydride, acetic acid, methyl iodide, sulfuric acid and hydrochloric acid. The products from these reactions of esterification, methylation, acetylation and halogenation will be characterized by Fourier-transforminfrared spectroscopy (FTIR). The use of this technique allowed us to detect the main absorption bands related to the C¼O bonds, C-Cl, R-COOR and CO, thus confirming the efficiency of modification reactions of the graft copolymer chain.
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    Development of propolis nanoemulsion with antioxidant and antimicrobial activity for use as a potential natural preservative.
    (2019) Seibert, Janaína Brandão; Silva, Jessica Paola Bautista; Amparo, Tatiane Roquete; Petit, Alicia; Pervier, Pauline; Almeida, Juliana Cristina dos Santos; Azevedo, Mariana Costa; Silveira, Benila Maria; Brandão, Geraldo Célio; Souza, Gustavo Henrique Bianco de; Teixeira, Luiz Fernando de Medeiros; Santos, Orlando David Henrique dos
    Propolis has demonstrated potential use as food preservative but it presents strong and unpleasant flavor that alters the sensory characteristics foods. A nanoemulsion was proposed to carry the Brazilian propolis extracts for use as natural food preservative. Antimicrobial and antioxidant activities and chemical constituents of the extracts were investigated. The latter were made by sequential extraction using different solvents (hexane, ethyl acetate and ethanol). Antimicrobial activity was evaluated by agar diffusion and microdilution methods and antioxidant activity by DPPH and ABTS assays. Extracts showed antibacterial and antioxidant activity, highlighting the ethanolic which contained artepillin-C, kaempferide, drupanin and p-coumaric acid as main compounds by LC-MS analysis. The nanoemulsion developed by phase inversion method was characterized and stable under thermal-stress and centrifugation conditions. Biological properties evaluated were effectively maintained by the formulation. It was concluded that the nanoemulsion can be used as a food preservative, preventing degradation and masking the propolis off-flavor.
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    In silico approach of secondary metabolites from Brazilian herbal medicines to search for potential drugs against SARS-CoV-2.
    (2021) Amparo, Tatiane Roquete; Seibert, Janaína Brandão; Almeida, Tamires Cunha; Costa, Fernanda Senna Ferreira; Silveira, Benila Maria; Silva, Glenda Nicioli da; Santos, Orlando David Henrique dos; Souza, Gustavo Henrique Bianco de
    The new severe acute respiratory syndrome coronavirus (SARS-CoV-2) recently emerged as a worrying pandemic, with many confirmed cases and deaths globally. Therefore, there is a clear need for identifying effective therapeutic options and a review of secondary metabolites related to Brazilian herbal medicines was performed as a strategy for the discovery of new antiviral agents. To confirm this potential, an in silico screening of the identified compounds identified was also evaluated. The review was performed by the PubMed database and the selected natural compounds were subjected to in silico analysis such as QSAR, molecular docking and ADMET. 497 secondary metabolites were identified from 23 species. The in silico assays indicated 19 potential anti-SARS-CoV-2 compounds, being triterpenes and phenolic compounds. The indicated compounds showed a high affinity with proteins considered as the main molecular targets against SARS-CoV-2 and parameters indicated low toxicity. In addition to Brazilian medicinal plants, these compounds can be found in other species and they can be a base for the synthesis of other anti-COVID-19 drugs. Therefore, this review is important to conduct researches that address the emerging need for drugs in COVID-19 treatment.
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    Preparation, characterization, and biological activity against Artemia salina of news copolymer PMMA-g-PEG derivatives incorporated with fluconazole.
    (2018) Silveira, Benila Maria; Novack, Kátia Monteiro; Marcondes, Hélcio Cassemiro; Santos, Viviane Martins Rebello dos
    The graft copolymer PMMA‐g‐PEG meets characteristics of their origin polymers: PMMA resistance and transparency and appropriate structure, including good solubility in water and organic solvents, lack of toxicity, and easy processing of the PEG, with inserted between the pharmacologically active polymers and can act as drugs or may be used as carriers for other drugs. The PMMA‐G‐PEG copolymer and their derivatives are synthesized previously and subsequently, the copolymer derivatives passed through the process of emulsification and incorporation of the drug fluconazole. Emulsified and Incorporated derivatives copolymers are characterized by Fourier‐transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential thermal analysis (DTA), X‐ray diffraction (XRD), and scanning electron microscopy (SEM) after the incorporation, in order to evaluate their effectiveness. The efficiency of incorporation is evaluated as well as the influence of polymer chain complexity in the incorporated fluconazole. Their toxicities are determined against Artemia salina Leach. The LD50 values have also been obtained for these copolymers.
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    Reuse of hot trub as an active ingredient with antioxidant and antimicrobial potential.
    (2020) Costa, Fernanda Senna Ferreira; Amparo, Tatiane Roquete; Seibert, Janaína Brandão; Silveira, Benila Maria; Silva, Regislainy Gomes da; Pereira, Deise Inocêncio; Barbosa, Ramon Gontijo Garcia; Santos, Orlando David Henrique dos; Brandão, Geraldo Célio; Teixeira, Luiz Fernando de Medeiros; Vieira, Paula Melo de Abreu; Souza, Gustavo Henrique Bianco de
    The reuse of agro-industrial residues is vital to minimize their environmental impact and alternatives for their application are needed. In this research, we evaluated the chemical composition as well as antioxidant and antibacterial activities of the extract from hot trub, that is the second solid waste obtained during the brewing process. Total phenolic and favonoids compounds were determined by colorimetric assays and the compounds were identifed by UHPLC-DAD-MS/MS. Antioxidant activity was evaluated by ABTS and DPPH methods. Antibacterial activity against Gram-positive and Gram-negative bacteria was analyzed by agar difusion and microdilution methods. Cytotoxicity was evaluated against murine fbroblast L929 cell line by MTT assay. The results showed that the content of phenolic and favonoid compounds ranged according to the fractions from 8.237 to 13.390 mg GAE/g and from 0.019 to 1.643 mg QE/g, respectively. The compounds cohumulone, cohulupone, hulupone/adhulupone, isoxanthohumol, xanthohumol, hydroxytricyclocolupone epimers, hydroxytricyclolupone/ hydroxytricicloadlupone epimers and nortricyclocolupone were suggested. Higher antioxidant activity was observed for the crude ethanol extract. The hexane fraction presented the lowest MIC value against Gram-positive bacteria, as well as lower cytotoxicity. These results are promising and indicate a great potential for the reuse of this byproduct as a source of natural antioxidant and for the microbiological applications, which consequently would reduce the environmental impact.
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    Study of controlled release of PMMA-g-PEG copolymer and derivatives incorporated with the indomethacin drug.
    (2018) Azevedo, Maria Luíza Schaefer; Silveira, Benila Maria; Novack, Kátia Monteiro; Barboza, Ana Paula Moreira; Neves, Bernardo Ruegger Almeida; Santos, Viviane Martins Rebello dos
    Synthetic polymers are made up of repeated monomeric units, and this gives them a very versatile appearance, making them useful in many areas of science. One is the pharmaceutical, which correlates the properties of the polymer with the active principle, so they can be used as an excipient or in the controlled release system. The PMMA‐g‐PEG4000 has characteristics derived from its precursors, that are pharmacologically active. When we incorporate drugs into this structure, the polymer can act on the controlled release, lessening the toxic character of the drug and producing fewer side effects. In this work, incorporations of the drug indomethacin were made in the PMMA‐g‐PEG copolymer and derivatives (PMMA‐g‐PEG4000 ETIL and PMMA‐g‐PEG4000 ACET). The samples were characterized by infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), thermogravimetric analysis (TGA), and atomic force microscopy (AFM) measurements. For each sample, the controlled release was performed in a total time of 4 h and the efficiency of the modified structures was verified.