Navegando por Assunto "Atividade antioxidante"

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Acesso aberto (Open Access)
Antioxidant capacity and biological activity of essential oil and methanol extract of Hyptis crenata Pohl ex Benth
(2009-03) REBELO, Monaliza Maia; SILVA, Joyce Kelly do Rosário da; ANDRADE, Eloisa Helena de Aguiar; MAIA, José Guilherme Soares
The essential oils of fresh and dried leaves and fine stems of Hyptis crenata furnished the following yields: 1.4% and 0.9%. The main volatile constituents were α-pinene (22.0%; 19.5%), 1,8-cineole (17.6%; 23.2%), β-pinene (17.0%; 13.8%), camphor (4.7%; 11.6%), limonene (5.4%; 4.4%) and γ-terpinene (3.5%; 2.4%), totalizing more than 70% in the oils. The DPPH radical scavenging activity (EC50, 16.7 + 0.4 µg/mL) of the methanol extract was comparable to BHT (19.8 ± 0.5 µg/mL) showing a significant antioxidant activity. The oils showed low activities. The amount of total phenolics (TP, 373.0 + 15.9 mg GAE/g) and trolox equivalent (TEAC, 226.8 + 0.5 mg TE/g) confirmed the antioxidant activity of the methanol extract that can be attributed to the presence of polar phenolic compounds. In the brine shrimp bioassay the lethal concentrations (LC50) for the oil and methanol extract were 6.7 + 0.2 µg/mL and 13.0 + 3.7 µg/mL, respectively, providing important evidence of their biological activities.
Acesso aberto (Open Access)
Atividade antibacteriana, antioxidante e citotóxica in vitro do extrato etanólico da entrecasca da planta Ouratea hexasperma (EEEOH) (A. St-Hil.) Baill var. Planchonii Engl
(Universidade Federal do Pará, 2015-09-17) COSTA, Glauber Vilhena da; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390
Ouratea hexasperma (Ochnacea), popularly known as "cerrado barbatimão" is a very common plant in the brazilian cerrado region and has been used for the treatment of microbial infections and inflammation. Therefore, this study aimed to evaluate the antioxidant activities, quantifying total flavonoid content (TFT), antibacterial and cytotoxicity of ethanol extract of the bark of Ouratea hexasperma (EEBOH) as well as perform their phytochemical characterization. The plant was collected in the state of Amapá, and then was held extraction of dry bark through the cold maceration with 96% ethanol solution in a 2: 8 (w/v) for 1 day, forming the EEBOH. The phytochemical characterization was performed by testing chromatic/precipitation tube and flavonoid content was measured by assay complexation with aluminum using quercetin as standard (40-0,62μg/mL), and the total antioxidant capacity by the spectrophotometric method discoloration radical ABTS•+ (2,2'azino-bis-3-etilbenzotiazolin 6-sulfonic acid) - TEAC. The antimicrobial activity of EEBOH was tested against gram-positive and gram-negative bacteria, using the microdilution techniques broth with staining by resazurin, to determine the Minimum Inhibitory Concentration (MIC), and grown in petri dish with subsequent count of colony forming units (CFU) for obtaining the Minimum Bactericidal Concentration (MBC). The evaluation of the cytotoxicity of EEEOH human peripheral blood leukocytes. Mononuclear peripheral blood cells incubated with different concentrations of the extract and without stimulation (negative control). The cytotoxicity of EEEOH were tested using human peripheral blood leukocyte, mononuclear cells, with different extract concentrations and without stimulation (negative control), and incubated and maintained at 37 ° C, 98% humidity and 5% CO2 for 24 hours, NO and MDA were read in an ELISA spectrophotometer and different optical readings. The primary EEBOH phytochemical analysis showed the presence of tannins, saponins and flavonoids. The TFT in the extract was 1467 ± 264μg equivalents quercetin/g EEBOH. The antioxidant capacity by TEAC method showed high antioxidant activity, with no difference in antioxidant capacity (TEAC) between those concentrations of the extract. The EEBOH showed good antibacterial activity, mainly against gram-positive bacteria. The cytotoxicity was obtained by linear regression concentration able to kill 50% of cells (CC 50%) whose amount was 2231,5mg/mL, confirming that the crude extract has low cytotoxicity against human leukocytes, under the conditions tested. In the production of NO and MDA it found that the EEOC was not able to induce NO production of the concentrations tested. As well, no increase MDA of concentration induces changes when compared to the negative control (RPMI), confirming the low in vitro cytotoxicity of the extract. Statistical analyzes were performed by ANOVA one way and Turkey. In concluded that the EEBOH have antibacterial, antioxidant and low cytotoxicity.
Acesso aberto (Open Access)
Avaliação da composição química e atividades biológicas dos óleos essenciais de Lippia gracilis e Lippia origanoides da Amazônia oriental
(Universidade Federal do Pará, 2012-10-17) FRANCO, Caroline da Silva; SILVA, Joyce Kelly do Rosário da; http://lattes.cnpq.br/2278686174214080; MAIA, José Guilherme Soares; http://lattes.cnpq.br/1034534634988402
The genus Lippia is known for its aromatic character and medicinal use of its species as an alternative therapy. Essential oils of Lippia gracilis and L. origanoides collected in Pará and Maranhão were obtained by hydrodistillation and were rich in monoterpenes. The major compounds oil of L. gracilis were thymol (72.5%), p-cymene (9.3%) and thymol methyl ether (5.4%); for oil of L. origanoides were thymol (45.8%), p-cymene (14.3%), -terpinene (10.5%) and carvacrol (9.9%). The oils had potential larvicide against Artemia salina with LC50 values of 7.4 ± 0,2 μg.mL-1 to L. origanoides and 18.7 ± 0.2 μg.mL-1 to L. gracilis, both more active than lapachol (EC50 = 21.2 ± 2.2 μg/ ml). The essential oil of L. gracilis showed moderate scavenging capacity DPPH with EC50 value = 35.7 ± 3.32 μg.mL-1 about 8 times less active than the standard trolox (EC50 of 4.5 ± 0.1). Furthermore, the oil L. gracilis proved to be a good natural fungicide against the phytopathogen C. sphaerospermum with limit of detection of 5 μg, about 10 times less active than miconazole (DL = 0.5 μg). Moreover, the oil L. origanoides no showed significant activity (DL = 100μg).
Acesso aberto (Open Access)
Avaliação da composição química, atividade antioxidante e antimicrobiana do óleo de cipó-de-alho (Mansoa standleyi) (Steyerm.) A. H. Gentry (Bignoniaceae) obtido via extração supercítica
(Universidade Federal do Pará, 2019-05-31) URBINA, Glides Rafael Olivo; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580
Mansoa standleyi is popularly known as "cipó-de-alho" because of its characteristic garlic odor (Allium sativum). The plant has an inhibitory effect on bacteria and fungi growth. The objective of this work was to evaluate the chemical composition, antioxidant and antimicrobial activity of the oil obtained from M. standleyi leaves via supercritical fluid extraction (SFE) and conventional extraction (Hydrodistillation). The SFE tests were performed using supercritical CO2, static extraction time of 30 min and dynamic time of 180 min, CO2 flow of 2.5 L/min and raw material mass of 10 g. The temperature and pressure variables were selected in order to obtain a difference in the CO2 density (𝜌𝐶𝑂2) in the 35 and 45 ºC isotherms combined with the pressure values of 100, 200, 300, and 400 bar. The results obtained allow us to verify that the global yield values of SFE on dry basis show significant differences between them (p≤0.05), with values varying from 0.87 to 2.02%. The highest average found refers to 400 bar/35 ºC condition (𝜌𝐶𝑂2 = 972.26 kg/m3). However, in Hydrodistillation extraction the oil yield was 0.14%. The results of phytochemical screening by high performance thin layer chromatography (HPTLC) evidenced the presence of terpenes, fatty acids, phenolic compounds, and flavonoids. It was demonstrated the presence of substances with antioxidant activity for all oils obtained with SFE, being observed a better identification in the oils obtained at high pressures. In the quantitative analysis of chemical composition, it was observed that the values ranged from 31.87 to 72.06 mg EAG/g oil in the content of total phenolic compounds. In relation to the antioxidant activity, the values ranged from 457.64 to 2475.55 EC50 expressed in g of oil/g of DPPH, the best results being obtained in the condition of 400 bar/35 ºC. In the fatty acid profiles of M. standleyi oil obtained by SFE, the results indicated that there was a difference in the fatty acids qualitative composition detected, in function of the operational extraction condition, where the presence of linoleic (≅95%), palmitic (≅12%), and oleic (≅5%) acid was observed. The chemical constituents identified in the obtained oil by Hydrodistillation were identified as sulfur compounds, phenols, and alcohols. The antimicrobial activity in vitro analysis showed that the oil obtained by SFE presents an antibacterial action against Stapphylococcus aureus and Escherichia coli. Finally, M. standleyi oil represents an alternative for future use in the treatment of diseases caused by microorganisms.
Acesso aberto (Open Access)
Avaliação de atividade antimicrobiana e perfil fitoquimíco de plantas medicinais utilizadas por comunidades remanescentes de quilombos no Marajó
(Universidade Federal do Pará, 2020-12-28) SILVA, Suzana Helena Campelo Nogueira da; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390; https://orcid.org/ 0000-0002-3328-5650; SILVA, Consuelo Yumiko Yoshioka e; http://lattes.cnpq.br/8337688339279747; https://orcid.org/ 0000-0002-9120-1910
The ethnopharmacological survey is recognized as one of the most viable methods in the search for new medicinal plants, with the ultimate purpose of producing medicines of natural or semi-synthetic origin. In this sense, the remaining communities of Amazonian quilombolas (Marajó-PA) carry with them a great deal of knowledge about the use of medicinal plants, which has been passed down for generations in Mararajo soil, promoting the value of popular knowledge and its applicability in future studies. The objective of this study is to provide scientific support for the traditional use of plants in the treatment of dermatological diseases in quilombola communities in Marajó that do not yet have an adequate chemical and / or pharmacological study. During the fieldwork carried out between 2017 and 2018, 13 communities were interviewed, in which 7 plants with use in skin diseases were cited. Such plants were collected, and their exsiccates were prepared. After botanical identification by a qualified professional, an extensive bibliographic review was carried out, after which 3 plants were selected for phytochemical and pharmacological study (in vitro in Microsporum and Staphylococcus aureus). In addition, they were subjected to ORAC antioxidant and TP total polyphenols tests. The phytochemical profile was analyzed using liquid chromatography coupled to mass spectrometry (LC-MS) providing 17 chemical constituents, belonging to the flavonoid class. The results of the in vitro tests showed an antibacterial potential of the ethanolic extract of the leaves of C. alatus (MIC) of 0.625 µg / mL and (CBM) of 0.734 µg / mL and of the ethanol extract of the roots D. floribunda (MIC) of 125, 0 ug / mL and 200.0 μg / mL (CBM) compared to S. aureus, with emphasis on the F3 fraction (MIC) 25.0 μg / mL and (CBM) of 132.0 which presented the highest bacterial inhibition. Therefore, the results contributed to the validation of popular use and chemical characterization of the species that presented antimicrobial potential, which can be a promising candidate for herbal medicine.
Acesso aberto (Open Access)
Desenvolvimento e caracterização tecnológica de micropartículas de arrabidaea chica (h & B) B. Verl. obtidas por spray dryer
(Universidade Federal do Pará, 2012-08) SAMPAIO, Rita de Cássia Almeida; BARBOSA, Wagner Luiz Ramos; http://lattes.cnpq.br/1372405563294070; SILVA JÚNIOR, José Otávio Carréra; http://lattes.cnpq.br/4437885351749994
This work aimed the technological development of particulate dosage forms obtained from extraction solution (tincture) from aerial parts of Arrabidea chica (Pariri), using the spray drying. We investigated the influence of processing aids (maltodextrin and arabic gum, alone and in a mixer) in drying performance and product properties. A. chica tincture was concentrated on a rotary evaporator to obtain the concentrated extract (CE) which was added to the processing aids and subjected to spray drying. The drying process was assessed through determination of product recovery and thermal efficiency. Microparticles (ES) were evaluated for residual moisture, water activity, average particle diameter, bulk density, packing density and flow properties, thermal profile and IR spectroscopy. The chemical monitoring was performed by UV-vis spectrophotometer, using chemical marker flavonoids (Ft), polyphenols (Pt) and total tannins (Tt) in the A. chica. The antioxidant activity of the product was evaluated by DPPH and chemiluminescence. The moisture content of the ES had their values in the range 2.77 to 4.69% being within the specified. The water activity values were below 0.2, which supports the physical and chemical stability and microbiological of dried products. The percentage of degradation of chemical markers in ES regard to CE was in the range 24-46% for Ft, 48-56% for Pt and 53-72% to Tt, which may be associated with thermal degradation and oxidation of the same compounds. In TLC analysis, tincture, CE and ES showing the luteolin and kaempferol patterns indicate that the drying process does not cause the loss of these compounds. The particle size distribution shows that the ES showed an average diameter of about 10 μm and the particles had a spherical morphology and with some rough surface. The flowability indices and accommodation of the powders obtained results are typical of powders with low flowability and compressibility characteristics. The antioxidant activity of ES presented values between 32.17 to 44.53 mg / mL. In the colorimetric analysis, the parameters proved the yellowish-red color. The recovery of product was in the range 60-65% and the thermal efficiency values were between 36% and 39%. Analyses of infrared spectroscopy and thermal analysis proved important tools in the physico-chemical characterization and quality control systems microparticulate obtained.
Acesso aberto (Open Access)
Estudo de métodos de extração, quantificação dos polifenóis totais, avaliação das atividades antioxidantes e antimicrobianas da casca do caule de Croton palanostigma Klotzsch
(Universidade Federal do Pará, 2017-02-22) RODRIGUES, Cintya Cordovil; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306; FARIA, Lênio José Guerreiro de; http://lattes.cnpq.br/7428609361678173; https://orcid.org/0000-0002-9534-9998
The Croton palanostigma is popularly known as "dragon blood" and used in folk medicine for the treatment of inflammatory diseases and wound healing. This paper proposes a study between the methodologies of conventional mining and extraction in supercritical carbon dioxide of stem bark of C. palanostigma, aiming to evaluate the extracts obtained income, the amount of total polyphenols, activities, antioxidant and anti-microbial. For the extraction process was conventional used jacketed extractor glass, in addition to a factorial design experiment of three factors and three levels of type Box-Behnken, with the objective of determining which variables (temperature, the extraction time and the relationship between mass/solvent) could influence the process, extraction for quantification of total polyphenols was used the method of Folin-Ciocalteau, with some changes and using the chart acid as a standard of reference, to analyze the antioxidant activity, we used the method of IC50, which measures the concentration needed to reach 50%of decrease in absorbance of DPPH radical and to the analysis antibiological was used the method of microdilution, whose goal was the determination of the minimum inhibitory concentration (CIM) Of all the tests ahead of the bacterial and fungal studied. The extraction methods used were efficient to obtain the extracts, with some qualitative differences, such as for example: color, viscosity and flavor. Quantitatively, the technique of conventional extraction presented a higher yield in their tests, however the same demanded much more time to process and greater amount of material used, both as botanist of solvent, in addition to all the variables assessed in this study were considered significant for the process, while the extraction supercritical the time used was significantly lower, as well as a lesser amount of botanical material and the co-solvent used (ethyl alcohol). For the quantification of total polyphenols found that the conventional extraction test 9 (T=45ºC; t=30 min; g/mL=1:2) was less efficient than those obtained by extracting supercritical (Test 1; T=40ºC; P=100 bar and Test 3; T=60ºC; P=300 bar) and having significant variables for the analysis time and relationship between mass and solvent. For antioxidant activity the best result was to extract conventional (IC50=30.71%) in relation to the test 3 (T=60ºC; P=300 bar) to extract supercritical (IC50=52.36) and having the variables, time and temperature its favorable conditions for the process. To analyze microbial all extracts obtained with the conventional extraction showed, in at least one of their concentrations, inhibitory activity against at least one of the pathogenic strains used in the test. For the samples obtained from the extraction in supercritical carbon dioxide to test 2 (T:60 ºC; P:200bar) showed no inhibitory activity against any bacterial strain used in the test, strain, bacterial Enterobacter did not suffer disqualification for none of the samples of supercritical carbon dioxide at a temperature of 60°C and E. coli also did not inhibit forward samples of extraction supercritical except test 1(T=40ºC; P=100 bar).
Acesso aberto (Open Access)
Extração de Compostos Antioxidantes de Cissus sicyoides L. com Tecnologia Supercrítica e Determinação da Atividade Anti-inflamatória no Modelo de Lesão Medular
(Universidade Federal do Pará, 2023-05-11) RODRÍGUEZ SALAZAR, Marielba de Los Ángeles; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-4433-6580
Cissus sicyoides L. or Cissus verticillata L., also known as vegetable insulin, is a plant that has a potent anti-inflammatory activity, due to its chemical composition, which stands out for the presence of compounds with high antioxidant activity. Supercritical technology is an appropriate alternative to extract antioxidant compounds from plant matrices. In this sense, the objective of this thesis was to perform the extraction of antioxidant compounds present in C. sicyoides through supercritical technology, using CO2 and EtOH as a co-solvent, and subsequently, in the supercritical extract, to evaluate the anti-inflammatory effect in the spinal cord injury model. For this, in the first experimental stage of the thesis, the identification of phenolic compounds by HPLC and the cytotoxic effect, on human red blood cells, of the extract of leaves and stems of C. sicyoides obtained by supercritical extraction was evaluated, in the operating condition of 50 °C/ 400 bar and 10 % EtOH (𝜌𝐶𝑂2+𝐸𝑡𝑂𝐻 = 953 kg/m3), compared to the extract obtained by conventional extraction (Soxhlet) and, finally, the antiinflammatory effect in the spinal cord injury model was evaluated. In the analysis of the extracts by HPLC, the UV/Visible spectral data revealed compounds with absorption bands at wavelengths characteristic of glycosylated flavonoids. The supercritical extract did not show a cytotoxic effect, as there was no disruption of red blood cell membranes. The in vivo assay demonstrated an apparent reduction in cell concentration in the area surrounding the lesion in the treated animals, suggesting an anti-inflammatory effect of the supercritical extract in the spinal cord injury model. In the second experimental stage of the thesis, the aim was to study the antioxidants present in each part of C. sicyoides (fruits, flowers, leaves and stems). Samples were evaluated for CFT content by the Folin-Ciocalteu method, which ranged from 9.30 to 141.04 mg GAE/g of sample, of FT by complexation with aluminum chloride from 1.03 to 44.02 mg QE /g of sample, its antioxidant activity by the DPPH method, the EC50 value varied between 162.83 to 453.25 g of sample/g of DPPH and by the FRAP method the values were 199.14 and 241.26 μM ferrous sulfate/ g sample. Thus, leaves and stems before and after SFE are rich in antioxidants, which justifies the high FT content, as well as the higher antioxidant activity by the tested methods. Finally, in the SFE process it was possible to obtain an extract with potential antioxidant activity, which can be used for biological applications.
Acesso aberto (Open Access)
Extração de compostos bioativos de folhas de croton matourensis Aubl. com CO2 Supercrítico: determinação da composição química, atividade antioxidante e atividade biológica
(Universidade Federal do Pará, 2022-05-06) BEZERRA, Fernanda Wariss Figueiredo Bezerra; CARVALHO JÚNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748; https://orcid.org/0000-0002-2324-6287
The Croton matourensis species has health benefits, due to its composition, which has a high concentration of bioactive compounds such as phenolic compounds, terpenes, phenolic acids and phenylpropanoids. The most used method to obtain its extracts is hydrodistillation, however the extraction with supercritical carbon dioxide (SC-CO2) is an environmentally friendly method, with high selectivity and capable of obtaining extracts with a high concentration of larixol, an oxygenated diterpene of high economic value and with several biological activities. In this context, the present thesis aimed to use supercritical technology to obtain extracts from leaves of C. matourensis with a high concentration of larixol and to evaluate its potential anti-inflammatory, neuroprotective and antiviral activity against the COVID-19 virus. For this, in the first stage of the thesis, the extraction of C. matourensis leaves with SC-CO2 was carried out under different conditions of temperature (40 and 50 °C) and pressure (100 to 400 bar), the supercritical extraction was compared with hydrodistillation (HD) and hexane extraction (HE) through the evaluation of the mass yield, chemical composition and antioxidant activity of the extracts, then the experimental model of focal ischemia in the motor cortex of rats was carried out using the extract obtained in the best operating condition with SC-CO2. The highest yields were obtained in HE (5.73 ± 0.26%) and in the condition at 50°C/400 bar (5.60 ± 0.06%), which were statistically equal (p > 0.05), the supercritical condition was more advantageous in obtaining larixol (48.49%) compared to HE (2.93%). The extracts obtained by the different methods showed a high value of total phenolic compounds (51.81 ± 2.03 to 79.53 ± 1.19 mgGAE/g of extract), total flavonoids (2.50 ± 0.20 - 6.89 ± 0.45 mgQE/g of extract) and antioxidant activity with maximum inhibition percentage equal to 83.26 ± 0.58% at a concentration of 14 mg/mL. The focal cerebral ischemia study revealed that the animals treated with the C. matourensis extract showed a greater reduction in the lesion area than those treated with the control solution (Tween 5%), suggesting its potential anti-inflammatory and neuroprotective effect. In the second stage of the thesis, an in silico study was carried out to evaluate the interactions between the larixol ligand and four SARS-CoV-2 receptors. The molecular docking results showed that the mode of interaction played a fundamental role in the interaction with larixol, mainly in the interaction with Spike- protease. The study showed through the affinity energy that the ligand had stable conformations, forming a stable complex with the receptors, conforming to the catalytic site of the receptors. Molecular docking, molecular dynamics and Gibbs free energy data showed that larixol can bind to the binding compartment of receptors, evidencing its potential role as an antiviral agent or agent used in conjunction with other therapies that provide a line of defense against diseases associated with the coronavirus. Thus, the thesis showed that the extract of C. matourensis leaves obtained with SC-CO2 showed a high concentration of larixol, with potential anti-inflammatory, neuroprotective and antiviral activities, presenting potential to be applied as an input in the food, cosmetic and pharmaceutical industries.
Acesso aberto (Open Access)
Funcionalidades de peptídeos provenientes de biomassas de oleaginosas amazônicas
(Universidade Federal do Pará, 2025-04-22) PANTOJA, Gabriela Vieira; FONTANARI, Gustavo Guadagnucci; http://lattes.cnpq.br/6654478241936919; HTTPS://ORCID.ORG/0000-0002-8417-263X; MARTINS, Luiza Helena da Silva; http://lattes.cnpq.br/1164249317889517; https://orcid.org/0000-0003-1911-4502
The use of agro-industrial by-products has been increasingly emphasized, as it focuses on sustainability and resource scarcity issues. Moreover, industrial processing by-products may also contain bioactive molecules. Bioactive peptides are molecules that exhibit a wide range of functionalities, including antimicrobial and antioxidant activities. Therefore, the aim of this study was to obtain protein hydrolysates with antioxidant and antimicrobial activity from the residual cakes of Amazonian biomasses tucumã (Astrocaryum vulgare), murumuru (Astrocaryum murumuru), and andiroba (Carapa guianensis) through enzymatic hydrolysis. To achieve this, the protein extraction was first optimized, and once the conditions of pH, ratio, and extraction time were defined, concentrated proteins were obtained and subsequently subjected to enzymatic hydrolysis using trypsin and alcalase. These hydrolysates were tested for phenolic compounds, antioxidant activity, antimicrobial activity, and separated by highperformance liquid chromatography (HPLC). The results of the study were positive regarding antioxidant activity, with tucumã hydrolysates showing the highest content. The andirobaalcalase and tucumã-trypsin hydrolysates exhibited moderate microbial inhibition activity, with this result tending, according to Pearson correlation, to be due to the peptide fractions obtained. Thus, it was possible to conclude that the use of residual oilseed cakes from the Amazon for the extraction of bioactive peptides is a viable practice for generating high-value by-products.
Acesso aberto (Open Access)
Geoprópolis produzida por diferentes espécies de abelhas: atividades antimicrobiana e antioxidante e determinação do teor de compostos fenólicos
(Universidade Federal do Pará, 2015-05-15) LIMA, Marcus Vinicius Dias de; MONTEIRO, Marta Chagas; http://lattes.cnpq.br/6710783324317390
Among meliponineos or stingless bees the most important are Melipona quadrifasciata (Mandaçaia), Melipona marginata (Manduri) and Tetragonisca angustula (Jataí). One of their product is geopropolis, a balsamic and resinous substance with complex chemical composition, collected from shoots, seepage and other parts of the plant tissue by these bees, which transformed it through enzymatic process by adding secretions and earth or clay, alone or in combination. Among the chemicals components, highlights the presence of phenolic compounds, diterpenes, triterpenes, essential oils and many other. The most studied propolis activity are antibacterial and antifungal, in addition to antiviral, immunomodulatory, anti-tumor, anti-inflammatory and antioxidant. Therefore this work aim to evaluate the antimicrobial activity, through determination of Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Trolox equivalent antioxidant capacity assay (TEAC), beyond the determination of the levels of flavonoids and phenolics compounds (Folin-Cioucalteu method and complexation with aluminum chloride, respectively) using geopropolis samples from different bees species (Melipona quadrifasciata, Melipona marginata and Tetragonisca angustula). All the geopropolis samples exhibit antimicrobial activity against gram-positive bacteria, wherein the Manduri Bee showed the lowest MIC and MBC; only Mandaçaia species showed moderate activity against gram-negative bacteria. The Manduri's geopropolis showed higher content of phenolics compounds and flavonoids, followed by Mandaçaia's geopropolis and both were in accordance with the parameters established by current legislation, wherein the Manduri's geopropolis also present high total antioxidant levels compared with other bees. It was noted that the antimicrobial activity of geopropolis extracts were not directly associated with high levels of phenolic compounds, including flavonoids.
Acesso aberto (Open Access)
Identification and antioxidant activity of several flavonoids of Inga edulis leaves
(2007) SOUZA, Jesus Nazareno Silva de; SILVA, Evaldo Martins da; SILVA, Milton Nascimento da; ARRUDA, Mara Silvia Pinheiro; LARONDELLE, Yvan; ROGEZ, Hervé Louis Ghislain
A methanol-water extract of Inga edulis leaves was fractionated to identify the polyphenolic compounds. The identified compounds were gallic acid, catechin, epicatechin, myricetin-3-rhamnopyranoside, quercetin-3-glucopyranoside and quercetin-3-rhamnopyranoside. The antioxidant activity of the extract and of pure polyphenols was measured by the ORAC assay and compared with the Total Phenolic (TP) content. The dry crude extract presented very high values for ORAC (11.16 mmol TE per g) and TP (496.5 mg GAE per g). The identified compounds were responsible for 9.53 % and 12.10 % of the ORAC value and TP content of the Inga edulis leaf extract, respectively.
Acesso aberto (Open Access)
Isoeleuterol e isoeleuterina: potenciais marcadores químicos da tintura de Eleutherine plicata Herb (Iridaceae) e atividades microbiológica e antioxidante
(Universidade Federal do Pará, 2008-12-30) MALHEIROS, Luiz Claudio da Silva; VIEIRA, José Maria dos Santos; http://lattes.cnpq.br/6807452375674442; BARBOSA, Wagner Luiz Ramos; http://lattes.cnpq.br/1372405563294070
Eleutherine plicata Herb. is an Iridaceae, popularly known as marupazinho, widely used by people to treat diarrhea. With the bulb of the plant is about a cup of tea, which is used to treat infestations caused by amoeba. The plant material used in this study was collected in Belém do Pará and their identification by comparison of botany was deposited in exsiccates Paraense Emilio Goeldi Museum under nº 10543. The ethanol extract was prepared by percolation from the bulb previously dried and crushed. After drying the ethanol extract was suspended in a solution hydroalcoholic (1:1) and subjected to partition with solvents of increasing polarity. With the ethanol extract and the fractions were performed eighteen tests to detect classes of secondary metabolites. The ethanol extract and the fractions hexanic and chloroform, showed a positive result for naphthoquinones, anthraquinones and steroids and triperpenoids. The analysis by thin-layer chromatography fractions of ethanol extract and hexane and chloroform, showed areas susceptible to methanolic solution of KOH 10%, indicating the presence of quinones in these samples. The evaluation of the antimicrobial activity of ethanol extract and fractions hexanic and chloroform with strains of C. albicans, S. aureus, E. coli and P. aeruginosa, showed that the chloroform fraction is the most active, presenting the largest halos of inhibition of microbial growth, possibly containing a higher concentration of active constituents. The chemical constituents isoeleutherol and isoeleutherine were isolated from chloroform fraction, and were characterized chemically using RMN 1H e 13C, compared with the literature. The ethanol extract, isoeleutherol and isoeleutherine were submitted to evaluation of their antioxidant activies, and showed weak activity when compared with BHT.
Acesso aberto (Open Access)
New isoflavones from the leaves of Vatairea guianensis Aublé
(2013-11) SOUZA, Ronilson Freitas de; MARINHO, Victor Hugo de Souza; SILVA, Geilson Alcantara da; COSTA JUNIOR, Livio Martins; SILVA, Joyce Kelly do Rosário da; BASTOS, Gilmara de Nazareth Tavares; ARRUDA, Alberto Cardoso; SILVA, Milton Nascimento da; ARRUDA, Mara Silvia Pinheiro
Four isoflavones were isolated from Vatairea guianensis Aublé leaves and identified as 5,3'-dihydroxy-4'-methoxy-2",2"-dimethylpyrano-(5",6":8,7)-isoflavone ( 1: ), 5,7-dihydroxy-3',4'-methylenedioxy-8-prenyl-isoflavone ( 2: ), 5,3'-dihydroxy-4'-methoxy-7-O-β-glucopyranoside-8-prenyl-isoflavone ( 3: ) and derrone ( 4: ) together with five triterpenes identified in mixture, lupeol, α-amyrin, β-amyrin, germanicol and betulinic acid. Substances 1: 3: are novel natural products, although 1: and 2: have been cited as synthetic products. However, all these compounds are first reported from this species. Their chemical structures were elucidated based on their 1D and 2D nuclear magnetic resonance (NMR) data and high resolution mass spectrometry. The ethanol extract from the leaves and 1: 3: were evaluated for their potential in scavenging DPPH• (2,2-diphenyl-1-picrylhydrazylradical) and the results showed that the extract presented high activity (IC50 = 6.2 ± 0.4 µg mL-1), while the isolated compounds showed low antioxidant power (IC50 ≥ 29.5 ± 2.5 µg mL-1) when compared to Trolox (IC50 = 4.5 ± 0.4 µg mL-1).
Acesso aberto (Open Access)
Obtenção de extratos padronizados em antioxidantes naturais: aproveitamento dos resíduos da ucuúba (Virola surinamensis)
(Universidade Federal do Pará, 2018-03-21) OLIVEIRA, Kalene de Almeida; COSTA, Roseane Maria Ribeiro; http://lattes.cnpq.br/0537372052713559
Acesso aberto (Open Access)
Otimização da pasteurização da polpa de jambolão (Syzygium cumini lamarck)
(Universidade Federal do Pará, 2014-11-21) AMÉRICO, Gilciane Vergolino; CARVALHO, Ana Vânia; http://lattes.cnpq.br/7856575452724939; LOPES, Alessandra Santos; http://lattes.cnpq.br/8156697119235191
The Syzygium cumini Lamarck fruits, popular known as jambolan, are a source of anthocyanin and antioxidant. This study aimed to optimize the thermic pasteurization of the jambolan pulp, with the purpose to inactivate the enzymes, the bioactive compounds and the antioxidant activity retention. Physical analyses: transverse length (2,49cm), longitudinal length (1,68cm) and percent yield (57,22%); and physicochemical: moisture (89.43%) ash (0.27%), lipid (0.23%), protein (0.72%), acidity (5.99% citric ac.), soluble solids (9,17 ° Brix), pH (3.34), total phenolic (182.01 mgGAE.100g-1), total anthocyanin (93.56 mg.100g-1) and antioxidant activity by DPPH method (EC50 = 4552.26 g / gDPPH) and ABTS (18,48 μMTrolox / g) were performed. Due to a resistance while trying to flow the jambolan pulp in the pasteurizer pipes, the pulp was diluted and complied with the national legislation (Brasil, 2003) for tropical juice. The methodology used was a central composite design (2²), using as independent variables: temperature (°C) and time (s), and as response variables: total phenolic compounds, total anthocyanin, antioxidant activity (DPPH and ABTS) and enzymatic activity (POD and PPO). The enzymes of the jambolan tropical juice were completely inactivated, except for POD in the test treated with 85ºC/39sec. The independent variables and the interaction of them didn’t influence significantly at 95% of confidence level in the results obtained to generate predictive models of the characteristics evaluated, except for the total phenolic content. The best condition to obtain a maximum retention of the compounds analyzed and the complete inactivation of the enzymes was the temperature 92ºC and time 70sec for tropical juice of jambolan which was pasteurized.
Acesso aberto (Open Access)
Planejamento e desenvolvimento de derivados do muscimol com propriedades antioxidantes
(Universidade Federal do Pará, 2019-12-09) SOUSA, Alanna Crystine Lima Farias de; BORGES, Rosivaldo dos Santos; http://lattes.cnpq.br/4783661132100859; https://orcid.org/0000-0003-4072-7573
Muscimole is a psychoactive izoxazole compound extracted from mushrooms of the genus Amanita muscaria has been studied as a GABA inhibitor due to behavioral genes, since its structural structure is based on mammalian neurotransmitters GABA and glutamic acid. Due to its high selectivity and its own potential for neural activity, it is able to act as a drug, since it has a higher affinity for the GABAA receptor than GABA. Since the 1980s studies suggesting that GABA and muscimol are related to serotonin concentration, where increased GABA concentration or muscimol injection increases serotonin concentration and decreases inactive product after serotonin. oxidation, 5-HIAA. For this reason, this work aimed to plan and develop muscimol derivatives as an alternative for increase the serotonin using antioxidant activity. For this reason, this work aimed to plan and develop muscimole derivatives as an alternative for the treatment of anxiety and depression. For this, was used the drug planning method known as bioisosterism, which is characterized by being compounds or subunits of bioactive substances with similar structural characteristics, as well as similar physical and chemical properties with the ability to present analogous biological properties, can be agonists or antagonists. Firstly, a study was made of the groups that are responsible for the biological activity through the muscimole pharmacophores, where the groups that interact with the GABAA receptor are the -NH2 groupings, the isoxazole ring, as well as the oxygen present in the carbonyl. Then molecular modeling was performed, which was performed using the DFT B3LYP 6-311G (2d, 2p) method to verify the values of HOMO, LUMO, GAP, ionization potential (IP), bond energy dissociation, hydrogen atom transfer and single electron transfer, where it was found that the derivative S1 presented values equal -7.61 eV, -1.36 eV, -6.25 eV, 205.87.85 kcal/mol, 80.81 kcal/mol, -15.45 kcal/mol e -6.99 kcal/mol, respectively. The derivative S2 presented values of -6.80 eV, -1.08 eV, 5.72 eV, 198.41 kcal/mol, 77.73 kcal/mol, -18.53 kcal/mol e -0.47 kcal/mol, respectively. When compared with GABA, it was found that they are reactive, among which derivative S2 is more reactive, presenting lower GAP value compared to S1, and with PI values, it was found that derivative S1 has a lower electron donor capacity than derivative S2, highlighting that the best route is through the hydrogen donation mechanism. Then, the regioisomers derivatives were synthesized with a yield for S1 and S2 of 74,08% and 60,42%, respectively, as well as characterization through the melting point, where the derivative S1 had equal melting point. at 114,5 ° C - 115 ° C and S2, 182,5 ° C, showing that the synthesized molecules are pure, since they were compared with the data in the literature. With these data it is possible to say that muscimol derivatives have high antioxidant activity.
Acesso aberto (Open Access)
Produção e avaliação da atividade antioxidante de metabólitos secundários de Piper divaricatum G. Meyer sob diferentes condições de cultivo
(Universidade Federal do Pará, 2015-08-06) CORPES, Rosana Silva; SILVA, Joyce Kelly do Rosário da; http://lattes.cnpq.br/2278686174214080
Many species of the genus Piper are widely distributed in the Amazon and various biological applications because of large structural diversity of its secondary metabolites. The species Piper divaricatum, is endemic in the Amazon and produces in its essential oil high concentrations of methyleugenol (50-90%), an phenylpropanoid with antioxidant and fungicidal properties. Because of its potential applications, the objective of this study was to establish the in vitro cultivation and comparing the biosynthesis of secondary metabolites and antioxidant properties with the in vivo cultivation. For establish the in vitro culture were used shoot apexes on Murashige e Skoog medium with addition of regulator BAP 0.5 mg.mL-1. For in vivo cultivation, micropiles were propagated in the greenhouse in vermiculite and adding nutritious Murashige e Skoog solution. The volatile compounds identified in the leaves of seedlings grown in vivo were methyleugenol, β-elemene and E-β-ocimene, which did not differ from in vivo cultivation, with the exception of 90 days. The in vitro culture of roots was not efficient to produce phenylpropanoids and presented a very different profile compared to the in vivo cultivation of terpenes. In general, for plants in vitro cultivated there was no statistically significant difference in the phenolics compounds content and antioxidant activity in the leaves. However, the antioxidant activity of roots was significant. The results support the hypothesis that in vitro regenerated plants can synthesize metabolites similar the matrix plant and maintain their biological properties.
Acesso aberto (Open Access)
Secagem de açaí branco por liofilização e em leito de jorro: influência da concentração e de diferentes agentes carreadores nas características físicas, químicas, bioativas e colorimétricas do pó obtido
(Universidade Federal do Pará, 2024-04-05) BARROS, Hellen Carvalho; COSTA, Cristiane Maria Leal; http://lattes.cnpq.br/0581730621014796; FARIA, Lênio José Guerreiro de; http://lattes.cnpq.br/7428609361678173; https://orcid.org/0000-0002-9534-9998
The objective of this study was to analyze how the use of four different carrier agents (modified starch, gum arabic, maltodextrin and hydrolyzed collagen) and different concentrations (10, 20 and 30%) influence the white açaí powder produced by lyophilization and in a bed of gush. Yield, moisture, total polyphenols, antioxidant activity, hygroscopicity, solubility, fluidity, color, chemical structure, and morphology were the responses evaluated. In freeze-drying, the yield of the process (≥ 75.40%) and the moisture content of white açaí powder (≤ 4.93 g 100 g- 1) did not differ statistically (p ≤ 0.05), regardless of the agent carrier used. In spouted bed drying, the addition of modified starch or hydrolyzed collagen promoted higher process yield (≥ 42.70%). However, the white açaí produced with hydrolyzed collagen was the only one that had a moisture content ≥ 6.00 g 100 g-1. In both drying processes, powders produced with modified starch were less soluble (≤ 48.96%), despite low hygroscopicity (≤ 13.73 g 100 g-1). Samples produced with maltodextrin or gum arabic showed higher levels of total polyphenols (≥ 8.52 mg EAG g-1) and antioxidant activity (≥ 42.75 μmol ET g-1). In addition, they were more soluble (≥ 94.36%), fluid (11 to 15% according to the carr index), and better preserved the original color of the pulp to the detriment of other formulations. The chemical structure of white açaí powders obtained with different carrier agents was like that of the pulp, indicating efficient encapsulation of bioactive compounds and good preservation of functional groups present in the original raw material, even after drying processes.
Acesso aberto (Open Access)
Síntese, capacidade antioxidante e estudo comparativo entre fenilhidrazonas e chalconas como derivados do paracetamol
(Universidade Federal do Pará, 2014) BELEZA FILHO, Raimundo Ferreira Gouvea Pimentel; BORGES, Rosivaldo dos Santos; http://lattes.cnpq.br/4783661132100859
The prostaglandin-endoperoxide synthase (PGES) and cytochrome P-450 are key enzymes in human, which are responsible for analgesic effect and toxicity of acetaminophen, respectively. Acetaminophen or paracetamol is a widely used over-the-counter analgesic and antipyretic drug and appears to be safe if used in normal therapeutic doses, but large doses of ACP produce hepatic and/or renal injury in humans and in experimental animals. At moment, the design of new acetaminophen derivatives has few impacts for its clinical applications of safe acetaminophen derivative. Thus, in this work a series of acetaminophen derivatives based on chalcone and hydrazone analogy was been investigated using quantum chemical calculations at the DFT/B3LYP theory level, with the 6-31G* basis sets. The HOMO, IP, BDEOH, and spin density contribution for the oxidation of an initial electron or hydrogen atom abstraction from the phenolic hydroxyl group was related with the quenching reactivity of tyrosyl radical to give N-acetyl-p-benzosemiquinone imine (NAPSQI). The second hydrogen abstraction was related with the chemistry reaction between amide group and hydroxyl radical to give N-acetyl-p-benzoquinone imine (NAPQI). The lowest BDEOH values were related with higher quenching values of the tyrosyl radical and the stability was related with the spin density for the initial electron or hydrogen abstractions. The highest BDENH values were related with small NAPQI formation and LUMO values with reactivity of NAPQI-like Michael system. Our results showed that some analogous may be a good strategy for safer drug design of analgesic compounds. The compounds were synthesized and their antioxidant property was estimated using theoretical methods. Some compounds can be good antioxidant. A proposed mechanism for the interaction between hydrazone derivatives and PGES was realized using molecular properties.