DEFAR - Artigos publicados em periódicos

URI permanente para esta coleçãohttp://www.hml.repositorio.ufop.br/handle/123456789/531

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Autor: search.filters.author.Oliveira, Alaíde Braga deTem arquivos: Sim

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Agora exibindo 1 - 10 de 19
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    High-resolution mass spectrometry identification and characterization of flavonoids from Fridericia chica leaves extract with anti-arbovirus activity.
    (2022) Cruz, Ana Flávia Gomes da; Reis, Adriana Cotta Cardoso; Sousa, Jordano Augusto Carvalho; Vaz, Luana Beatriz Araújo; Silva, Breno de Mello; Magalhães, Cíntia Lopes de Brito; Kohlhoff, Markus; Oliveira, Alaíde Braga de; Brandão, Geraldo Célio
    Plant extracts are complex mixtures that are difficult to characterize, and mass spectrometry is one of the main techniques currently used in dereplication processes. Fridericia chica is a species with medicinal uses in Latin American countries, used in the treatment of inflammatory and infectious diseases. Extracts of this plant species are characterized by the presence of anthocyanidins. In this study, using high-resolution mass spectrometry coupled with liquid chromatography, it was possible to determine the molecular formula of thirty-nine flavonoids. Fragmentation analysis, ultraviolet spectrum and nuclear magnetic resonance data allowed the partial characterization of the structures of these compounds. The spectral dataset allowed the identification of a series of flavones in addition to the desoxyanthocyanidins common in extracts of the species. The occurrence of some of the proposed structures is uncommon in extracts of species of the Bignoniaceae family, and they are reported for the first time in the extract of this species. Quantitative analyses of total flavonoids confirmed the high content of these constituents in the species, with 4.09 ± 0.34 mg/g of dry plant material. The extract under study showed low in vitro cytotoxicity with CC50 ≥ 296.7 ± 1.4 μg/mL for Vero, LLC-MK2 and MRC-5 cell lines. In antiviral activity assays, inhibition of the cytopathic effects of Dengue, Zika and Mayaro viruses was observed, with EC50 values ranging between 30.1 and 40.9 μg/mL. The best result was observed against the Mayaro virus, with an EC50 of 30.1 μg/mL.
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    Anti-zika activity of Ouratea semiserrata and dereplication of its constituents.
    (2021) Ferreira, Gabriel Monteze; Silva, Breno de Mello; Souza, Gustavo Henrique Bianco de; Oliveira, Alaíde Braga de; Brandão, Geraldo Célio
    Zika virus is an arbovirus that has vector mosquitoes of the genus Aedes. In adult humans, the infection may be asymptomatic or present mild symptoms such as itching and low fever. However, the infection is associated with other severe problems, which encouraged investigations for an effective treatment against this virus. This work evaluated the potential anti-Zika virus effect of the ethanolic extract of Ouratea semiserrata (Mart. & Nees) Engl., Ochnaceae, a medicinal plant popularly used in Brazil for the treatment of viral infections. The extract of the stems was prepared by cold percolation using ethanol as solvent and its content dereplicated by ultra-high-performance liquid chromatography-diode array detector-tandem mass spectrometry. Phenolic com- pounds including rutin, catechin, and epicatechin were identified as the major constituents. The antiviral activity was tested in vitro against Zika virus by the MTT colorimetric method. The ethanol extract inhibited the viral replication cycle with an EC50 of 37.5 μg/ml, and at the concentration of 100 μg/ml, a 100% inhibition of the viral cytopathic effect was obtained. Rutin and epicatechin inhibited viral cytopathic effect in Vero cells with EC50 > 50.00 μg/ml.
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    Extraction and fractionation effects on antiplasmodial activity and phytochemical composition of Palicourea hoffmannseggiana
    (2021) Ohashi, Leticia Hiromi; Gontijo, Douglas da Costa; Nascimento, Maria Fernanda Alves do; Margalho, Luciano Ferreira; Brandão, Geraldo Célio; Oliveira, Alaíde Braga de
    The present study on Palicourea hoffmannseggiana, which was collected at Marapanim, state of Pará, Brazil, comprises the preparation of different stem and leaf extracts and fractions. Ethanol, hydroethanol, and water extracts were prepared by several methods and evaluated for in vitro activity against resistant Plasmodium falciparum (W2 strain), disclosing a low parasite growth inhibition effect ( < 50 %). Dereplication by UPLC-DAD-ESI −MS of the leaf ethanol extract showed the presence of two known alkaloids, lyalosidic and strictosidinic acids, along with a sinapoyl ester of lyalosidic acid, with m/z 719.33 [M +H] + , which is possibly a new monoterpene indole alkaloid representative. Sequential liquid-liquid acid-base alkaloid separations from the leaf ethanol extract as well as directly from leaf powder afforded fractions of increased parasite growth inhibition, reaching up to 92.5±0.7%. The most bioactive fractions were shown to contain the β-carboline alkaloids harmane and 4-methyl-β-carboline, along with N-methyl-tryptamine and N-acetyl-tryptamine, while monoterpene indole alkaloids were detected in inactive fractions of these processes. The present results demonstrate that these preliminary fractionation methods can lead to significantly active fractions supporting an adequate scale-up to carrying out the isolation of anti-plasmodial compounds.
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    Dereplication of Palicourea sessilis ethanol extracts by UPLC-DAD-ESI-MS/MS discloses the presence of hydroxycinnamic acid amides and the absence of monoterpene indole alkaloids.
    (2020) Samulski, Gabriela Bontempo; Gontijo, Douglas da Costa; Moreira, Nayara Couto; Brandão, Geraldo Célio; Oliveira, Alaíde Braga de
    Secondary metabolites characterization of ethanol extracts of Palicourea sessilis leaves and stems by UPLC-DAD ESI-MS/MS led to putative identification of hydrolysable tannins in leaf extract (ESI negative mode) while hydroxycinnamic acid amides (HCA) such as N-p-coumaroylputrescine and N-feruloylagmatine were detected in both leaf and stems extracts in the ESI positive mode. Secondary metabolites quantification data showed a higher content of total phenolic in the leaf extract while the total alkaloids contents are statistically equivalent in both of the extracts. Furthermore, monoterpene indole alkaloids were not detected in both extracts. The presence of HCA is here firstly reported for a Palicourea species. This finding increases the classes of secondary metabolites occurring in this genus.
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    Himatanthus bracteatus stem extracts present antiflavivirus activity while an isolated sesquiterpene glucoside present only anti-Zika virus activity in vitro.
    (2019) Silva, Marlene Lourenço da; Stehmann, João Renato; Serafim, Mateus Sá Magalhães; Vale, Valdicley Vieira; Gontijo, Douglas da Costa; Brandão, Geraldo Célio; Kroon, Erna Geessien; Oliveira, Alaíde Braga de
    The hexane and ethanol extracts from Himatanthus bracteatus (Apocynaceae) stems were evaluated for antiviral activity against Zika virus, yellow fever virus and dengue virus 2 and for cytotoxicity in Vero cells by MTT assay. The ethanol extract showed good antiviral activity against the three viruses with selective indexes (SI) > 10 and its fractionation led to the isolation of the known plumieride that was active only against Zika virus (SI of 15.97).
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    Antioxidant study indicative of antibacterial and antimutagenic activities of an ellagitannin-rich aqueous extract from the leaves of Miconia latecrenata.
    (2019) Gontijo, Douglas da Costa; Gontijo, Pablo Costa; Brandão, Geraldo Célio; Diaz, Marisa Alves Nogueira; Oliveira, Alaíde Braga de; Fietto, Luciano Gomes; Leite, João Paulo Viana
    Ethnopharmacological relevance: Several plant species of Miconia genus are commonly used in Brazilian folk medicine as anti-inflammatory agents and for the treatment of infectious diseases. Infusions and extracts of Miconia species are also reported as analgesic, antimicrobial, antimalarial, antioxidant, anti-inflammatory, antinociceptive, antimutagenic, and antitumoral. Aim of the study; To determine the phytochemical composition of an aqueous extract of Miconia latecrenata leaves and to evaluate its antioxidant, antibacterial, antimutagenic and antigenotoxic activities. Materials and Methods: The following methods were used for the different effects: I) antioxidant - β-carotene/linoleic acid, lipid peroxidation, and DPPH• radical scavenging; II) antibacterial - agar well diffusion and MIC methods); III) antimutagenic assays - Ames Test; and IV) antigenotoxic - Plasmid cleavage test. The phytochemical analysis and phenolic quantification were carried out by UPLC-DAD-ESI-MS/MS and colorimetry, respectively. In addition, statistical correlation analysis was performed aiming to evaluate the Pearson correlation between phenolic compounds and biological assays. Results: A high content of tannins was observed and the ellagitannin isomers of 1,2,3,5-tris-galloyl-4,6-HHDP-glucose were identified as the main constituents of the leaves aqueous extract. High antioxidant effect, in different tests, high antibacterial activity to gram-positive and negative strains, as well as high antimutagenic activity were observed. Statistical analysis showed a high Pearson correlation for the tannin content in relation to the results of the antioxidant and antibacterial tests. In general, the antioxidant action of the aqueous extract showed low correlation with the antimutagenic activity. Conclusions: The present results confirmed the expectations regarding the pharmacological profile of M. latecrenata supporting its therapeutic potential in relation to ROS/RNS related disorders. Furthermore, the phenolic compounds of M. latecrenata can act, in turn, minimizing or inhibiting the biological macromolecules damage, especially DNA.
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    Mangifera indica leaves extract and mangiferin modulate CB1 and PPARγ receptors and others markers associated with obesity.
    (2019) Brito, Larissa Froede; Gontijo, Douglas da Costa; Toledo, Renata Celi Lopes; Barcelos, Rafael Mazioli; Oliveira, Alaíde Braga de; Brandão, Geraldo Célio; Sousa, Lirlândia Pires de; Ribeiro, Sônia Machado Rocha; Leite, João Paulo Viana; Fietto, Luciano Gomes; Queiroz, José Humberto de
    This study aimed phytochemical characterization (UPLC-DAD-MS/MS) of ethanolic extract of the leaves from Mangifera indica (EMI) and Mangiferin (MAN), analysis of the cytotoxic (MTT) and anti-inflammatory potential (expression of TNF-α) of EMI and MAN in vitro. In addition, was evaluate the effect on the mRNA expression of genes (CB1, PPARγ, adiponectin, resistin and leptin) associated with adipogenesis in adipose tissue of rats fed a cafeteria diet. Thus, wistar rats were treated by gavage with EMI and MAN for several days (according to the post and co-treatments). The adipose tissue was weighed and checked the expression of different markers by RT-PCR. The presence of MAN as major compound in EMI was verified. Both EMI and MAN were not cytotoxic, with lower EMI expression of TNF-α. Furthermore, EMI and MAN had proadipogenic action on post-treatment, while in the co-treatment, EMI attenuated the effect of adipogenesis and MAN increased the adipogenic process.
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    Bioprospection for antiplasmodial activity, and identification of bioactive metabolites of native plants species from the Mata Atlântica biome, Brazil.
    (2019) Gontijo, Douglas da Costa; Leite, João Paulo Viana; Nascimento, Maria Fernanda Alves do; Brandão, Geraldo Célio; Oliveira, Alaíde Braga de
    A total of 33 extracts of eleven different plants species from Mata Atlântica biome, Brazil, and different fractions of the bioactive extracts were evaluated against chloroquine-resistant Plasmodium falciparum W2 strain by PfLDH method and cytotoxicity to HepG2 cells by the MTT assay, and chemically characterized by LC-DAD-ESI-MS/MS analysis. The results allowed the identification of Alchornea glandulosa, Miconia latecrenata, and Psychotria suterella as the most active plant species. Different flavonoids and tannins in Alchornea glandulosa and Miconia latecrenata besides alkaloids in Psychotria suterella were identified. Bioguided fractionation of A. glandulosa and M. latecrenata leaves extracts led to fractions exhibiting high parasite growth inhibition. Seven known alkaloids were identified in the P. suterella extract, and of these, only 5-carboxystrictosidine had been assayed for antiplasmodial activity what points to this species as the most promising among the eleven one assayed.
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    Synthesis by click reactions and antiplasmodial activity of Lupeol 1,2,3-Triazole derivatives.
    (2017) Borgati, Tatiane Freitas; Pereira, Guilherme Rocha; Brandão, Geraldo Célio; Santos, Juliana de Oliveira; Fernandes, Dayane Aparecida Morais; Paula, Renata Cristina de; Nascimento, Maria Fernanda Alves do; Soares, Luciana Ferreira; Lopes, Júlio César Dias; Souza Filho, José Dias de; Oliveira, Alaíde Braga de
    Lupeol, a triterpene frequently found in Asteraceae plant species, showed moderate to low activity in different strains of Plasmodium falciparum, the most virulent malaria etiological agents. In this work, lupeol was isolated from Parahancornia fasciculata, a plant that is used to treat malaria in the Amazonia region. In the search of more activity lupeol derivatives, five new 1,2,3-triazole hybrid molecules were synthetized by copper-catalyzed azide-alkyne cycloaddition. The antiplasmodial activity of the semi-synthetic compounds were evaluated by the lactate dehydrogenase assay; the lupeol propargyl ether was the only one to disclosing increased activity (half maximal inhibitory concentration-IC50-62.0 ± 1.92 μmol L-1) in relation to lupeol (IC50 117.00 μmol L-1). Therefore, this work revealed a new class of interesting lupeol derivatives that can be obtained by linking electron donors to the hydroxy group at C-3.
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    Identification of phenolic compounds and biologically related activities from Ocotea odorifera aqueous extract leaves.
    (2017) Gontijo, Douglas da Costa; Brandão, Geraldo Célio; Gontijo, Pablo Costa; Oliveira, Alaíde Braga de; Diaz, Marisa Alves Nogueira; Fietto, Luciano Gomes; Leite, João Paulo Viana
    Ocotea odorifera (Vell.) Rohwer is popularly used as food and flavoring. The aim of this study was to determine the chemical composition of the aqueous extract from O. odorifera leaves and evaluate the correlation of their phytochemical composition and biological activities. The antioxidant effect was determined by DPPH radical scavenging, b-carotene-linoleic acid and lipid peroxidation assays; the antibacterial activity was evaluated by the hole plate and MIC techniques and the antimutagenic activity was evaluated by the Ames test. Identification of phytochemicals was performed by LC–ESI/MS and the correlation between the phytochemical composition of the extract and the evaluated activities. The results allowed the identification of 13 phenolic compounds in the extract that exhibited high antioxidant activity and moderate antibacterial and antimutagenic action. Statistical analyses showed correlation of the total phenolic content with biologically related activities. The phytochemical analyses, together with the biological results, support the popular use of O. odorifera.