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Item 7-Chloroquinolinotriazoles : synthesis by the azide-alkyne cycloaddition click chemistry, antimalarial activity, cytotoxicity and SAR studies.(2014) Pereira, Guilherme Rocha; Brandão, Geraldo Célio; Arantes, Lucas Micquéias; Oliveira Junior, Haliton Alves de; Paula, Renata Cristina de; Nascimento, Maria Fernanda Alves do; Santos, Fábio Mendes dos; Rocha, Ramon Kleber da; Lopes, Júlio César Dias; Oliveira, Alaíde Braga deTwenty-seven 7-chloroquinolinotriazole derivatives with different substituents in the triazole moiety were synthesized via copper-catalyzed cycloaddition (CuAAC) click chemistry between 4-azido-7- chloroquinoline and several alkynes. All the synthetic compounds were evaluated for their in vitro activity against Plasmodium falciparum (W2) and cytotoxicity to Hep G2A16 cells. All the products disclosed low cytotoxicity (CC50 > 100 mM) and five of them have shown moderate antimalarial activity (IC50 from 9.6 to 40.9 mM). As chloroquine analogs it was expected that these compounds might inhibit the heme polymerization and SAR studies were performed aiming to explain their antimalarial profile. New structural variations can be designed on the basis of the results obtained.Item Angiotensin-converting enzyme inhibition by Brazilian plants.(2007) Braga, Fernão Castro; Serra, Carla Penido; Viana Júnior, Nilton de Souza; Oliveira, Alaíde Braga de; Côrtes, Steyner de França; Lombardi, Júlio AntônioThe potential antihypertensive activity of Brazilian plants was evaluated in vitro by its ability to inhibit the angiotensinconverting enzyme (ACE). Forty-four plants belonging to 30 families were investigated. Plants were selected based on their popular use as antihypertensive and/or diuretics. The following plants presented significant ACE inhibition rates: Calophyllum brasiliense, Combretum fruticosum, Leea rubra, Phoenix roebelinii and Terminalia catappa.Item Anti-malarial activity and toxicity assessment of Himatanthus articulatus, a plant used to treat malaria in the Brazilian Amazon.(2015) Vale, Valdicley Vieira; Vilhena, Thyago da Costa; Trindade, Rafaela Cabral dos Santos; Ferreira, Marlia Regina Coelho; Percário, Sandro; Soares, Luciana Ferreira; Pereira, Washington Luiz Assunção; Brandão, Geraldo Célio; Oliveira, Alaíde Braga de; Dolabela, Maria Fâni; Vasconcelos, Flávio deBackground: Plasmodium falciparum has become resistant to some of the available drugs. Several plant species are used for the treatment of malaria, such as Himatanthus articulatus in parts of Brazil. The present paper reports the phyto-chemistry, the anti-plasmodial and anti-malarial activity, as well as the toxicity of H. articulatus. Methods: Ethanol and dichloromethane extracts were obtained from the powder of stem barks of H. articulates and later fractionated and analysed. The anti-plasmodial activity was assessed against a chloroquine resistant strain P. falciparum (W2) in vitro, whilst in vivo anti-malarial activity against Plasmodium berghei (ANKA strain) was tested in mice, evaluating the role of oxidative stress (total antioxidant capacity - TEAC; lipid peroxidation – TBARS, and nitrites and nitrates - NN). In addition, cytotoxicity was evaluated using the HepG2 A16 cell-line. The acute oral and sub-chronic toxicity of the ethanol extract were evaluated in both male and female mice. Results: Plumieride was isolated from the ethyl acetate fraction of ethanol extract, Only the dichloromethane extract was active against clone W2. Nevertheless, both extracts reduced parasitaemia in P. berghei-infected mice. Besides, a significant reduction in pulmonary and cerebral levels of NN (nitrites and nitrates) was found, as well as in pulmonary TBARS, indicating a reduced oxidative damage to these organs. The ethanol extract showed low cytotoxicity to HepG2 A16 cells in the concentrations used. No significant changes were observed in the in vivo toxicity studies. Conclusions: The ethanol extract of H. articulatus proved to be promising as anti-malarial medicine and showed low toxicity.Item 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 CélioZika 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.Item 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 VianaEthnopharmacological 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.Item Antiviral activity and chemical characterization of Cissus erosa (Vitaceae) ethanol extracts.(2020) Reis, Adriana Cotta Cardoso; Moura, Hélia Maria Marques de; Silva, Breno de Mello; Oliveira, Alaíde Braga de; Brandão, Geraldo CélioCissus erosa (Vitaceae), popularly known in Brazil as Cipó-fogo, is a medicinal plant used in the treatment of warts and external ulcers. The present study aimed to evaluate the activity of stems and leaves ethanol extracts of C. erosa against the Dengue and Zika virus by the MTT colorimetric method and to carry on the phytochemical characterization of active extracts by high performance liquid chromatography coupled to mass spectrometry (UPLC-MS). Only the leaves ethanol extract showed anti-Dengue virus activity EC50 18.2 μg/ml (SI > 27.5) and low cytotoxicity for LLCMK2 cells (CC50 > 500 mg/ml). Both extracts (stems and leaves) showed anti-Zika virus activity with EC50 of 45.8 mg/ml and 82.8 mg/ml, respectively. These extracts presented CC50 of 309.2 μg/ml (leaves) and 387.6 μg/ml (stems) to Vero cells. Analysis by CCD and HPLC-DAD detected the presence of triterpenes, steroids, flavonoids and tannins. UPLC-MS analyses of these extracts, allowed the identification of the majority of flavonoids present known as vitexin, isovitexin, orientin, isoorientin and two flavones derivatives, methoxyluteolin-6(8)-C-hexosyl and luteolin-7,4’-di-O-glycosylflavone. The results of the phytochemical studies here described suggest that flavonoids and terpenoids are the substances that contribute to the antiviral activity of the ethanol extracts within this species.Item Antiviral activity of Fridericia formosa (Bureau) L. G. Lohmann (Bignoniaceae) extracts and constituents.(2017) Brandão, Geraldo Célio; Kroon, Erna Geessien; Souza Filho, José Dias de; Oliveira, Alaíde Braga deA phytochemical study of Fridericia formosa (Bignoniaceae) ethanol extracts of leaves, stems, and fruits was guided by in vitro assays against vaccinia virus Western Reserve (VACV-WR), human herpes virus 1 (HSV-1), murine encephalomyocarditis virus (EMCV), and dengue virus type 2 (DENV-2) by the MTT method. All the ethanol extracts were active against DENV-2, HSV-1, and VACV-WRwith best results for the fruits extract against DENV-2 (SI > 38.2). For VACV-WRand HSV-1, EC50 values > 200 𝜇g mL−1 were determined, while no inhibition of the cytopathic effect was observed with EMCV. Five compounds were isolated and identified as the C-glucosylxanthones mangiferin (1), 2-O-trans-caffeoylmangiferin (2), 2-O-trans-coumaroylmangiferin (3), 2- O-trans-cinnamoylmangiferin (5), and the flavonoid chrysin (4). The most active compound was 2-O-trans-coumaroylmangiferin (3) with SI > 121.9 against DENV-2 and 108.7 for HSV-1. These results indicate that mangiferin cinnamoyl esters might be potential antiviral drugs.Item 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 deA 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.Item Chemical constituents of Distictella elongata (Vahl) Urb. (Bignoniaceae).(2013) Simões, Leandro R.; Maciel, Glauber M.; Brandão, Geraldo Célio; Souza Filho, José Dias de; Oliveira, Alaíde Braga de; Castilho, Rachel OliveiraPectolinarina, uma flavona heterosídica, foi isolada do extrato etanólico das folhas de Distictella elongata (Vahl) Urb., além de uma mistura de ácidos ursólico, pomólico e oleanólico, além de β-sitosterol. Suas estruturas foram estabelecidas com base em análise espectral (RMN de 1H e 13C 1D e 2D) em comparação com a literatura. Esta é a primeira vez em que se relata a ocorrência deste flavonoide em uma espécies da família Bignoniaceae.Item Chemistry and antiviral activity of Arrabidaea pulchra (Bignoniaceae).(2013) Brandão, Geraldo Célio; Kroon, Erna Geessien; Souza, Danielle E. R.; Souza Filho, José Dias de; Oliveira, Alaíde Braga deThe aim of the present work was to carry out a bioguided isolation of antiviral chemical constituents from an ethanol extract of leaves from Arrabidaea pulchra (Cham.) Sandwith (EEAPL) that had shown in vitro activity in a previous screening using DNA and RNA viruses. The activity of EEPAL was evaluated against the DNA viruses Human herpesvirus 1 (HSV-1) and Vaccinia virus Western Reserve (VACV-WR) as well as against the RNA viruses Murine encephalomyocarditis virus (EMCV), and Dengue virus 2 (DENV-2) by the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) colorimetric assay. Cytotoxicity was determined in LLCMK2 and Vero cells and the Selectivity Indexes (SI) were calculated. The most potent effect was observed against DENV-2 (EC50 46.8 ± 1.6 μg mL−1; SI 2.7). For HSV-1 and VACV-WR EC50 values > 200 μg mL−1 were determined, while no inhibition of the cytopathic effect was observed with EMCV. Bioguided fractionation of EEAPL by partition between immiscible solvents followed by chromatography over a Sephadex LH20 column afforded two arylpropanoid glycosides, verbascoside (AP 1) and caffeoylcalleryanin (AP 2), along with a terpenoid, ursolic acid (AP 3). AP 1 and AP 3 exhibited similar anti-DENV-2 profiles, with SI values of 3.8 and 3.1, respectively, while AP 2 was the most effective anti-DENV-2 constituent, with a SI of 20.0. Our results show that A. pulchra leaves ethanol extract (EEAPL) affords compounds with antiviral activity, mainly against DENV-2.Item 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 deSecondary 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.Item 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 deThe 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.Item 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 CélioPlant 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.Item 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 deThe 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).Item 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 VianaOcotea 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.Item In vitro antitumor activity of sesquiterpene lactones from Lychnophora trichocarpha.(2014) Guimarães, Dênia Antunes Saúde; Raslan, Delio Soares; Oliveira, Alaíde Braga deAs lactonas sesquiterpênicas licnofolida e eremantolida C foram isoladas de Lychnophora trichocarpha Spreng. (Asteraceae), espécie vegetal nativa do cerrado brasileiro e popularmente conhecida por arnica brasileira. As lactonas sesquiterpênicas são conhecidas por apresentarem variadas atividades biológicas, incluindo atividade antitumoral. O presente artigo relata a avaliação da atividade antitumoral in vitro de licnofolida e eremantolida C frente a um painel de 52 linhagens de células tumorais, provenientes de tumores humanos referentes a nove principais tipos de câncer. Os testes foram conduzidos no National Cancer Institute, USA (NCI, USA). Licnofolida apresentou atividade significativa frente a 30 linhagens de células tumorais referentes a sete tipos de câncer, com valores de CI100 (concentração que inibe 100% do crescimento celular) entre 0,41 μM e 2,82 μM. Eremantolida C mostrou atividade significativa frente a 30 linhagens de células tumorais referentes a oito tipos de câncer, com valores de CI100 entre 21,40 μM e 53,70 μM. Licnofolida apresentou valores de concentração letal 50 % (CL50) para 30 linhagens de células tumorais humanas entre 0,72 e 10,00 μM, enquanto eremantolida C mostrou valores de CL50 para 21 linhagens entre 52,50 e 91,20 μM. Licnofolida apresentou um interessante perfil de atividade antitumoral. A presença na estrutura química da licnofolida de uma α-metileno-γ-lactona, além de dois grupos ésteres α,β-insaturados, podem ser responsáveis pela melhor atividade e maior citotoxicidade desta substância em relação à eremantolida C.Item 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 deThis 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.Item Synthesis and trypanocidal activity of ent-kaurane glycosides.(2007) Batista, Ronan; Humberto, Jorge Luiz; Chiari, Egler; Oliveira, Alaíde Braga deNovel ent-kaurane glucosides were synthezised by a Koenigs–Knorr reaction between C17 and C19 alcohols derived from kaurenoic acid and 2,3,4,6-tetra-O-acetyl-glucopyranosyl bromide, followed by the hydrolysis of the acetates. Main products were assayed in vitro and in vivo against blood trypomastigote forms of Trypanosoma cruzi, the aetiological agent of Chagas’ disease (American trypanosomiasis). The results allowed to establish structure–activity relationships among these derivatives, as well as pointed out the C19-methylester-C17-O-glucoside as a potential trypanocidal agent, whose trypanocidal profile was shown to be comparable to those of gentian violet and benznidazole.Item 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 deLupeol, 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.Item The positive inotropic effect of the ethyl acetate fraction from Erythrina velutina leaves on the mammalian myocardium : the role of adrenergic receptors.(2013) Passos, Amilton Gustavo da Silva; Gondim, Antônio Nei Santana; Campos, Danilo Roman; Cruz, Jader dos Santos; Garcia, Eduardo Antônio Conde; Araújo Neto, Vitor; Estevam, Charles dos Santos; Cerqueira, Sandra Valéria Santos; Brandão, Geraldo Célio; Oliveira, Alaíde Braga de; Vasconcelos, Carla Maria Lins deObjectives We studied the effects of ethyl acetate fraction (EAcF) obtained from Erythrina velutina leaves on mammalian myocardium. Methods The effect of EAcF on the contractility was studied using guinea-pig left atria mounted in a tissue bath (Tyrode’s solution, 29°C, 95% CO2, 5% O2) and electrically stimulated (1 Hz). Concentration-response curves of EAcF were obtained in the presence of propranolol (1 mm), nifedipine (1 mm) and in reserpinized animals (5 mg/kg). The involvement of l-type calcium current (ICa,L) on the EAcF effect was observed in cardiomyocytes of mice assessed using patch-clamp technique. Key findings EAcF (550 mg/ml) had a positive inotropic effect, increasing the atrial force by 164% (EC50 = 157 44 mg/ml, n = 6), but it was less potent than isoproterenol (EC50 = 0.0036 0.0019 mg/ml, n = 8). The response evoked by EAcF was abolished by propranolol or nifedipine. Reserpine did not alter the inotropic response of EAcF. Furthermore, an enhancement of the ICa,L peak (31.2%) with EAcF was observed. Chemical analysis of EAcF revealed the presence of at least 10 different flavonoid glycoside derivatives. Two were identified as vicenin II and isorhoifolin. Conclusions We conclude that EAcF increases the cardiac contractile force by increasing the l-type calcium current and activating the adrenergic receptor pathway.