15 results on '"Francisco W.Q. Almeida-Neto"'
Search Results
2. Antiproliferative activity on Trypanosoma cruzi (Y strain) of the triterpene 3β,6β,16β-trihidroxilup-20 (29)-ene isolated from Combretum leprosum
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Alexandre Magno Rodrigues Teixeira, Natália L. Aires, Hélcio Silva dos Santos, Wanderlei do Amaral, Francisco W.Q. Almeida-Neto, Ana Rafaela Freitas Dotto, Emanuel Paula Magalhães, Tiago Lima Sampaio, Edson Holanda Teixeira, Emanuelle Machado Marinho, Pedro de Lima-Neto, Márcia Machado Marinho, Emmanuel Silva Marinho, José Ismael Feitosa de Araújo, Alice Maria Costa Martins, and Ramon Róseo Paula Pessoa Bezerra de Menezes
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chemistry.chemical_classification ,Chagas disease ,biology ,Strain (chemistry) ,Combretum ,General Medicine ,biology.organism_classification ,medicine.disease ,Microbiology ,Triterpene ,chemistry ,Structural Biology ,Benznidazole ,Combretum leprosum ,medicine ,Trypanosoma cruzi ,Molecular Biology ,Ene reaction ,medicine.drug - Abstract
Chagas disease infects approximately seven million people worldwide. Benznidazole is effective only in the acute phase of the disease, with an average cure rate of 80% between acute and recent cases. Therefore, there is an urgent need to find new bioactive substances that can be effective against parasites without causing so many complications to the host. In this study, the triterpene 3β-6β-16β-trihydroxilup-20 (29)-ene (CLF-1) was isolated from Combretum leprosum, and its molecular structure was determined by NMR and infrared spectroscopy. The CLF-1 was also evaluated in vitro and in silico as potential trypanocidal agent against epimastigote and trypomastigote forms of Trypanosoma cruzi (Y strain). The CLF-1 demonstrated good results highlighted by lower IC50 (76.0 ± 8.72 µM, 75.1 ± 11.0 µM, and 70.3 ± 45.4 µM) for epimastigotes at 24, 48 and 72 h, and LC50 (71.6 ± 11.6 µM) for trypomastigotes forms. The molecular docking study shows that the CLF-1 was able to interact with important TcGAPDH residues, suggesting that this natural compound may preferentially exert its effect by compromising the glycolytic pathway in T. cruzi. The ADMET study together with the MTT results indicated that the CLF-1 is well-absorbed in the intestine and has low toxicity. Thus, this work adds new evidence that CLF-1 can potentially be used as a candidate for the development of new options for the treatment of Chagas disease. Communicated by Ramaswamy H. Sarma
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- 2021
3. In silico study of the potential interactions of 4′-acetamidechalcones with protein targets in SARS-CoV-2
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Alexandre Magno Rodrigues Teixeira, Francisco W.Q. Almeida-Neto, Maria Geysillene Castro Matos, Emmanuel Silva Marinho, Ramon Róseo Paula Pessoa Bezerra de Menezes, Márcia Machado Marinho, Paulo Nogueira Bandeira, Pedro de Lima-Neto, Carla F. C. Fernandes, Emanuelle Machado Marinho, Tiago Lima Sampaio, and Hélcio Silva dos Santos
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0301 basic medicine ,Steric effects ,Chalcone ,Stereochemistry ,medicine.medical_treatment ,Biophysics ,ACE2 ,Microbial Sensitivity Tests ,Virus Replication ,medicine.disease_cause ,Antiviral Agents ,Biochemistry ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Acetamides ,medicine ,SPIKE ,Humans ,Molecular Biology ,Coronavirus 3C Proteases ,Coronavirus ,chemistry.chemical_classification ,Protease ,SARS-CoV-2 ,Hydrogen bond ,Cell Biology ,Molecular Docking Simulation ,030104 developmental biology ,Enzyme ,chemistry ,Viral replication ,030220 oncology & carcinogenesis ,Molecular docking ,Spike Glycoprotein, Coronavirus ,Angiotensin-Converting Enzyme 2 ,Acetamide - Abstract
The sanitary emergency generated by the pandemic COVID-19, instigates the search for scientific strategies to mitigate the damage caused by the disease to different sectors of society. The disease caused by the coronavirus, SARS-CoV-2, reached 216 countries/territories, where about 20 million people were reported with the infection. Of these, more than 740,000 died. In view of the situation, strategies involving the development of new antiviral molecules are extremely important. The present work evaluated, through molecular docking assays, the interactions of 4′-acetamidechalcones with enzymatic and structural targets of SARS-CoV-2 and with the host’s ACE2, which is recognized by the virus, facilitating its entry into cells. Therefore, it was observed that, regarding the interactions of chalcones with Main protease (Mpro), the chalcone N-(4′[(2E)-3-(4-flurophenyl)-1-(phenyl)prop-2-en-1-one]) acetamide (PAAPF) has the potential for coupling in the same region as the natural inhibitor FJC through strong hydrogen bonding. The formation of two strong hydrogen bonds between N-(4[(2E)-3-(phenyl)-1-(phenyl)-prop-2-en-1-one]) acetamide (PAAB) and the NSP16-NSP10 heterodimer methyltransferase was also noted. N-(4[(2E)-3-(4-methoxyphenyl)-1-(phenyl)prop-2-en-1-one]) acetamide (PAAPM) and N-(4-[(2E)-3-(4-ethoxyphenyl)-1-(phenyl)prop-2-en-1-one]) acetamide (PAAPE) chalcones showed at least one strong intensity interaction of the SPIKE protein. N-(4[(2E)-3-(4-dimetilaminophenyl)-1-(phenyl)-prop-2-en-1-one]) acetamide (PAAPA) chalcone had a better affinity with ACE2, with strong hydrogen interactions. Together, our results suggest that 4′-acetamidechalcones inhibit the interaction of the virus with host cells through binding to ACE2 or SPIKE protein, probably generating a steric impediment. In addition, chalcones have an affinity for important enzymes in post-translational processes, interfering with viral replication., Graphical abstract Image 1, Highlights • Chalcones derivatives interacting with SARS-CoV-2 SPIKE protein. • Strong affinity with the ACE2 human host cells. • The 4′-acetamidechalcones can interfering with the virus replication.
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- 2021
4. Synthesis, structural and spectroscopic analysis, and antiproliferative activity of chalcone derivate (E)-1-(4-aminophenyl)-3-(benzo[b]thiophen-2-yl)prop‑2-en-1-one in Trypanosoma cruzi
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Débora H. Almeida de Brito, Francisco W.Q. Almeida-Neto, Lyanna R. Ribeiro, Emanuel P. Magalhães, Ramon R.P.P. Bezerra de Menezes, Tiago L. Sampaio, Alice M.C. Martins, Paulo N. Bandeira, Márcia M. Marinho, Emmanuel S. Marinho, Antônio C.H. Barreto, Pedro de Lima-Neto, Gilberto D. Saraiva, Kirley M. Canuto, Hélcio S. dos Santos, Alexandre M.R. Teixeira, and Nágila M.P. Silva Ricardo
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Inorganic Chemistry ,Organic Chemistry ,Spectroscopy ,Analytical Chemistry - Published
- 2022
5. Structural and spectroscopic analysis, ADMET study, and anxiolytic-like effect in adult zebrafish (Danio rerio) of 4′-[(1E,2E)-1-(2-(2′,4′-dinitrophenyl)hydrazone-3-(4-methoxyphenyl)allyl)aniline
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Matheus Nunes da Rocha, Francisco Rogênio da Silva Mendes, Mikael Amaro de Souza, Jane Eire Silva Alencar de Menezes, Francisco W.Q. Almeida-Neto, Maria Kueirislene Amâncio Ferreira, Hélcio Silva dos Santos, Mateus Rodrigues de Oliveira, Emmanuel Silva Marinho, Alexandre Magno Rodrigues Teixeira, A. C. H. Barreto, Márcia Machado Marinho, Kevin K.A. de Castro, Paulo Nogueira Bandeira, Pedro de Lima-Neto, Tigressa Helena Soares Rodrigues, and Débora Hellen Almeida de Brito
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GABAA receptor ,medicine.drug_class ,Chemistry ,Organic Chemistry ,Antagonist ,Pharmacology ,Anxiolytic ,Analytical Chemistry ,Inorganic Chemistry ,Pharmacokinetics ,Mechanism of action ,GABA receptor ,Flumazenil ,medicine ,medicine.symptom ,Diazepam ,Spectroscopy ,medicine.drug - Abstract
Benzodiazepines (GABA receptor agonists) and serotonin reuptake inhibitors (SSRIs) are the drugs of choice for the treatment of anxiety. However, they have considerable adverse effects, so it is important to discover new anxiolytic agents. In this work, the 4′-[(1E,2E)-1-(2-(2′,4′-dinitrophenyl)hydrazone-3-(4-methoxyphenyl)allyl)aniline (HYDRAZDN) was synthesized and characterized by 1H and 13C NMR, 2D-NMR, ATR-FTIR, FT-Raman, and UV-Vis spectroscopy, and their structural and spectroscopic proprieties were evaluated by quantum chemistry theoretical calculations. Properties such as drug-likeness and pharmacokinetics were also estimated. The anxiolytic-like effect of the compound was also evaluated using adult zebrafish (Danio rerio). The results showed that the HYDRAZDN compound caused a reduction in zebrafish locomotor activity and induced maximum permanence of zebrafish in the clear zone at a dose of 40 mg/kg, an effect similar to the effect of positive control diazepam (DZP: 40 mg/kg). To identify the mechanism of action of the anxiolytic effect of this compound, we used flumazenil, an antagonist at the benzodiazepine binding site at GABAA receptors. The treatment with the highest dose of HYDRAZDN (40 mg/kg) and DZP (40 mg/kg) caused anxiolytic behavior in the animals that spent most of their time in the dark region of the aquarium. This effect was reduced by flumazenil, indicating that anxiolytic activity of the synthesized hydrazone occurs through the GABAergic system.
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- 2022
6. Structural and spectroscopic analysis and evaluation of cytotoxic activity of 2-hydroxychalcones against human cancer cell lines
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Cláudia Pessoa, Priscila Teixeira da Silva, Murilo S. S. Julião, Alexandre Magno Rodrigues Teixeira, Aldeneide Soares de Paiva, Francisco Washington Araújo Barros-Nepomuceno, A. C. H. Barreto, Daniel Pascoalino Pinheiro, Paulo Nogueira Bandeira, Pedro de Lima-Neto, Antonio Linkoln Alves Borges Leal, Francisco W.Q. Almeida-Neto, Hélcio Silva dos Santos, and Emmanuel Silva Marinho
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Chalcone ,Organic Chemistry ,Carbon-13 NMR ,Quantum chemistry ,Analytical Chemistry ,Inorganic Chemistry ,chemistry.chemical_compound ,Ultraviolet visible spectroscopy ,chemistry ,Computational chemistry ,Proton NMR ,Molecular orbital ,Reactivity (chemistry) ,Spectroscopy - Abstract
Chalcones and their derivatives exhibit a broad spectrum of pharmacological activities, including antiproliferative activities. Accordingly, they are deemed robust anticancer candidates for cytotoxicity assays. Herein, we synthesized and characterized four chalcones using nuclear magnetic resonance (1H NMR and 13C NMR), Fourier transform Raman (FT-Raman), attenuated total reflection Fourier transform infrared (ATR-FTIR), and ultraviolet-visible (UV–vis) spectroscopy. Theoretical calculations of quantum chemistry were performed to obtain data regarding normal vibration modes, frontier molecular orbitals, molecular electrostatic potential maps, theoretical UV–vis spectra, and quantum chemical parameters expected for these chalcones. In addition, we evaluated the cytotoxic potential of these compounds. For synthesized compounds, quantum chemical calculations demonstrated excellent correlation with experimental data. The electronic properties revealed that chalcones 1 and 4 possess a higher electrophilic character, while chalcones 2 and 3 possess a higher nucleophilic character. Chalcone 3 demonstrated the highest value of HOMO energy, indicating the greatest propensity to donate electronic density among the four compounds. According to the HOMO-LUMO energy gap and global hardness, the reactivity of chalcones should follow the order 1
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- 2021
7. Synthesis, structural and spectroscopic characterization, in silico study, and antinociceptive effect in adult zebrafish of 2-(4-isobutylphenyl) -N'-phenylpropanohydrazide
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João Pedro da Hora, Márcia Machado Marinho, Antonio Wlisses da Silva, Francisco W.Q. Almeida-Neto, Paulo Freire, Tigressa Helena Soares Rodrigues, Jane Eire Silva Alencar de Menezes, Amanda Pereira de Sousa, Hélcio Silva dos Santos, Murilo Sérgio da Silva Julião, Paulo Nogueira Bandeira, Emmanuel Silva Marinho, Aldeneide Soares de Paiva, A. C. H. Barreto, Maria Kueirislene Amâncio Ferreira, Tatiana Rodrigues Garcia, and Alexandre Magno Rodrigues Teixeira
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biology ,010405 organic chemistry ,Stereochemistry ,In silico ,Organic Chemistry ,Infrared spectroscopy ,010402 general chemistry ,biology.organism_classification ,Ibuprofen ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,In vivo ,Molecular descriptor ,medicine ,Binding site ,Zebrafish ,Spectroscopy ,Derivative (chemistry) ,medicine.drug - Abstract
In this work, an ibuprofen derivative 2-(4-isobutylphenyl) -N'-phenylpropanohydrazide (ACPHZN) was synthesized and characterized by NMR, ATR-FTIR, FT-Raman, and UV-Vis spectroscopy, while their structural and spectroscopic properties were investigated using DFT calculations. In vivo study using animal model in an adult Zebrafish (Danio rerio), and molecular docking was performed. In addition, molecular descriptors of the properties of absorption, distribution, metabolism and excretion, and toxicity (ADMET) were obtained. The data calculated for ibuprofen derivative are in accordance with the experimental values. From the assays in adult zebrafish, it was found that the ibuprofen derivative was non-toxic and exhibited analgesic properties through the TRPA1, TRPV1 and TRPM8 channels. Molecular docking revealed six interactions of ACPHZN with residues of the capsaicin binding site, and a more favorable affinity energy (-9.0 kcal / mol). ADMET studies suggest that ACPHZN has a pharmacological principle as an oral drug based on a longer half-life in the human body.
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- 2021
8. Spectroscopic analysis by NMR, FT-Raman, ATR-FTIR, and UV-Vis, evaluation of antimicrobial activity, and in silico studies of chalcones derived from 2-hydroxyacetophenone
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Priscila Teixeira da Silva, Murilo Sérgio da Silva Julião, Paulo Nogueira Bandeira, Ana Carolina Justino de Araújo, Carlos Emídio Sampaio Nogueira, Hélcio Silva dos Santos, Jayze da Cunha Xavier, Priscila R. Freitas, Márcia Machado Marinho, A. C. H. Barreto, Henrique Douglas Melo Coutinho, Alexandre Magno Rodrigues Teixeira, Nitin Kumar, Francisco W.Q. Almeida-Neto, Emmanuel Silva Marinho, Thiago Sampaio de Freitas, and Janaína Esmeraldo Rocha
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chemistry.chemical_classification ,Chalcone ,Double bond ,010405 organic chemistry ,Organic Chemistry ,010402 general chemistry ,Antimicrobial ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,Analytical Chemistry ,Inorganic Chemistry ,Penicillin ,chemistry.chemical_compound ,chemistry ,Nucleophile ,Covalent bond ,medicine ,Efflux ,Spectroscopy ,Norfloxacin ,medicine.drug - Abstract
Six 2’-hydroxychalcones were synthesized and characterized by NMR, FT-Raman, ATR-FTIR, and UV-Vis. These chalcones alone and in combination with the ciprofloxacin, penicillin, and erythromycin antibiotics were tested against multiresistant strains of Staphylococcus aureus. It was also verified by in vitro and in silico studeis the capacity of these chalcones to inhibit the NorA efflux pump. The MICs values of ciprofloxacin were reduced in the presence of all tested chalcones. For norfloxacin antibiotic, the chalcones A1, A4, A5 and A6 promoted the reduced in the MIC values. The A2 chalcone was the only one to reduce the MIC values when associated with penicillin. Any chalcones were not able to reduce MIC values when associated with erythromycin. These results indicate that the synergistic effects demonstrated for the synthesized chalcones were influenced by the introduction of a furanic ring (A1), a chlorine atom and a methoxy group at the C4 position (A2 and A4), a second double bond (A5), and a fluorine atom at the C2 position (A6). The ADMET analysis predicts that the chalcones A2, A3, A5 and A6 have easier cell permeation. The nucleophilic region makes the A5 chalcone capable of covalently bonding with plasma proteins, and the presence of oxygenated aromatic substitutions makes the chalcones A1 and A4 more water-soluble and consequently easier to excrete. On the other hand, the substitution of the methoxy group of the A4 chalcone makes it more susceptible to O-demethylation reactions by the CYP3A4 isoenzyme. The molecular docking revealed that all six chalcones could hinder the binding of norfloxacin to the NorA efflux pump.
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- 2021
9. Physical-chemical characterization, controlled release, and toxicological potential of galactomannan-bixin microparticles
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Tamara Gonçalves de Araújo, Emmanuel Silva Marinho, Jane Eire Silva Alencar de Menezes, Francisco W.Q. Almeida-Neto, Selene Maia de Morais, Sônia Maria Costa Siqueira, Gilberto Dantas Saraiva, Antônia Fádia Valentim de Amorim, Hélcio Silva dos Santos, Nágila M.P.S. Ricardo, Luana Carvalho da Silva, Pedro de Lima-Neto, Alexandre Magno Rodrigues Teixeira, and Karla L.L. Pascoal
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chemistry.chemical_classification ,Organic Chemistry ,Bixin ,Infrared spectroscopy ,Polymer ,Chemical reaction ,Controlled release ,Analytical Chemistry ,Inorganic Chemistry ,Galactomannan ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Spray drying ,Particle ,Spectroscopy - Abstract
In this study, a spray drying technique was used to encapsulate bixin in the galactomannan polymer to give greater stability to this carotenoid. The microparticles were characterized using physical-chemical techniques, quantum chemical calculations, and evaluated the particle sizes, encapsulation efficiency, stability, controlled release, and toxicological potential. The bixin was successfully encapsulated, with an average size of 5.55 ± 0.50 µm, and infrared spectroscopy showed no chemical reaction between bixin and galactomannan during the encapsulation process. The values for the encapsulation efficiency were higher than 90 %, indicating that galactomannan was a good encapsulating agent. A stability test revealed that microencapsulation provides significant protection for bixin. It was observed that the microparticles were capable of releasing the pigment homogeneously and gradually. The absence of toxicity of these materials allows for their use within the food industry, since there is a need for new products that combine low toxicity, efficiency, and low cost.
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- 2021
10. Full Spectroscopic Characterization and Cytotoxicity Activity of Synthetic Dibenzalacetone Derivatives
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Carlos Emídio Sampaio Nogueira, Alexandre Magno Rodrigues Teixeira, Hélcio Silva dos Santos, Emmanuel Silva Marinho, Francisco W.Q. Almeida-Neto, Mauro Macedo de Oliveira, Cláudia Pessoa, Manoel Odorico de Moraes, Pedro de Lima-Neto, and Francisco Washington Araújo Barros-Nepomuceno
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010405 organic chemistry ,Chemistry ,Organic Chemistry ,Chromophore ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,Analytical Chemistry ,Characterization (materials science) ,Inorganic Chemistry ,Polarizability ,Biological property ,Cancer cell ,Density functional theory ,Cytotoxicity ,Spectroscopy - Abstract
Dibenzalacetone derivatives are organic compounds formed by two α , α ′ active sites that provide a large relocation of π-electrons. They have great polarizability that make them excellent chromophore and draw attention for their biological properties, mainly for their activity against nasopharyngeal, oral, colon, prostate and cervical cancer. Two dibenzalacetone derivatives, (1E,4E)-1,5-bis(4-ethoxyphenyl)penta-1,4-dien-3-one and (1E,4E)-1,5-bis(4-chlorophenyl)penta-1,4-dien-3-one, were synthesized. Spectroscopic characterizations as well as vibrational assignments were predicted using density Functional Theory (DFT) calculations with B3LYP exchange-correlation functional. Cytotoxicity assays of the synthesized compounds were performed against HCT-116, SNB and PC3 cells, showing promising results against cancer cells HCT-116.
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- 2021
11. Quantum computational investigations and molecular docking studies on amentoflavone
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Leonardo P. da Silva, Márcia Machado Marinho, Francisco W.Q. Almeida-Neto, Pedro de Lima-Neto, Emanuelle Machado Marinho, Alice Maria Costa Martins, Emmanuel Silva Marinho, Ricardo Pires dos Santos, and Ramon Róseo Paula Pessoa Bezerra de Menezes
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0301 basic medicine ,Antichagasic agent ,Amentoflavone ,NLO ,DFT ,Electronegativity ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Computational chemistry ,Electron affinity ,Reactivity (chemistry) ,lcsh:Social sciences (General) ,lcsh:Science (General) ,chemistry.chemical_classification ,Multidisciplinary ,Fukui analysis ,Biflavonoid ,030104 developmental biology ,chemistry ,Electrophile ,lcsh:H1-99 ,Density functional theory ,Ionization energy ,030217 neurology & neurosurgery ,lcsh:Q1-390 ,Research Article - Abstract
Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi, with approximately 6–7 million people infected worldwide, becoming a public health problem in tropical countries, thus generating an increasing demand for the development of more effective drugs, due to the low efficiency of the existing drugs. Aiming at the development of a new antichagasic pharmacological tool, the density functional theory was used to calculate the reactivity descriptors of amentoflavone, a biflavonoid with proven anti-trypanosomal activity in vitro, as well as to perform a study of interactions with the enzyme cruzain, an enzyme key in the evolutionary process of T-cruzi. Structural properties (in solvents with different values of dielectric constant), the infrared spectrum, the frontier orbitals, Fukui analysis, thermodynamic properties were the parameters calculated from DFT method with the monomeric structure of the apigenin used for comparison. Furthermore, molecular docking studies were performed to assess the potential use of this biflavonoid as a pharmacological antichagasic tool. The frontier orbitals (HOMO-LUMO) study to find the band gap of compound has been extended to calculate electron affinity, ionization energy, electronegativity electrophilicity index, chemical potential, global chemical hardness and global chemical softness to study the chemical behaviour of compound. The optimized structure was subjected to molecular Docking to characterize the interaction between amentoflavone and cruzain enzyme, a classic pharmacological target for substances with anti-gas activity, where significant interactions were observed with amino acid residues from each one's catalytic sites enzyme. These results suggest that amentoflavone has the potential to interfere with the enzymatic activity of cruzain, thus being an indicative of being a promising antichagasic agent., Antichagasic Agent; Biflavonoid; DFT; Fukui Analysis; NLO.
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- 2021
12. Structural characterization, electronic properties, and anxiolytic-like effect in adult zebrafish (Danio rerio) of cinnamaldehyde chalcone
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Francisco W.Q. Almeida-Neto, Jayze da Cunha Xavier, Paulo Nogueira Bandeira, Maria Kueirislene Amâncio Ferreira, Alexandre Magno Rodrigues Teixeira, Carlos Emídio Sampaio Nogueira, Hélcio Silva dos Santos, Jane Eire Silva Alencar de Menezes, Priscila Teixeira da Silva, Emmanuel Silva Marinho, and Francisco Ernani Alves Magalhães
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Chalcone ,animal structures ,medicine.drug_class ,Stereochemistry ,ved/biology.organism_classification_rank.species ,Danio ,010402 general chemistry ,01 natural sciences ,Anxiolytic ,Cinnamaldehyde ,Analytical Chemistry ,Anxiolytic like ,Inorganic Chemistry ,chemistry.chemical_compound ,medicine ,Model organism ,Zebrafish ,Spectroscopy ,Electronic properties ,biology ,010405 organic chemistry ,Chemistry ,ved/biology ,Organic Chemistry ,biology.organism_classification ,0104 chemical sciences - Abstract
Zebrafish is a model animal that is used for neurobehavioral studies. It is an excellent model organism for pharmacological studies and/or safety research at an early stage of drug development. In this work, the chalcone (2E, 4E)-1-(2‑hydroxy-3,4,6-trimethoxyphenyl)-5-phenylpenta-2,4‑dien‑1-one, was synthesized by the Claisen-Schmidt condensation from two natural products: 2‑hydroxy-3,4,6-trimethoxyacetophenone and cinnamaldehyde. The molecular structure of this compound was confirmed by spectroscopic methods such as NMR, Infrared, UV–vis, and quantum chemical calculations. In addition, the anxiolytic-like effect of the cinnamaldehyde chalcone in adult zebrafish (Danio rerio) was evaluated. The results showed that chalcone caused an approximately 80% reduction in zebrafish locomotor activity and induced maximum permanence of zebrafish in the clear zone (61.16%) at a dose of 0.5 mg kgl−1. The data suggest that the cinnamaldehyde chalcone has anxiolytic activity.
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- 2020
13. Characterization of the structural, spectroscopic, nonlinear optical, electronic properties and antioxidant activity of the N-{4’-[(E)-3-(Fluorophenyl)-1-(phenyl)-prop-2-en-1-one]}-acetamide
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Norberto K.V. Monteiro, Francisco Rogênio da Silva Mendes, Hélcio Silva dos Santos, Francisco W.Q. Almeida-Neto, Jane Eire Silva Alencar de Menezes, Kevin K.A. de Castro, Paulo Nogueira Bandeira, Pedro de Lima-Neto, Emmanuel Silva Marinho, Maria Kueirislene Amâncio Ferreira, and Leonardo P. da Silva
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Chalcone ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Infrared spectroscopy ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Inorganic Chemistry ,Delocalized electron ,chemistry.chemical_compound ,Physical chemistry ,Molecule ,Density functional theory ,Spectroscopy ,Fukui function ,Natural bond orbital ,Electronic density - Abstract
The molecule N-{4’-[(E)-3-(Fluorophenyl)-1-(phenyl)-prop-2-en-1-one]} chalcone (PAAPFBA) was recently synthesized due to the growing interest in the chemistry of the chalcone. The quantum chemical calculations were carried out to make a complete theoretical characterization (structural, spectroscopy, nonlinear optical, and electronic properties) employing three Density Functional Theory (DFT) methods like B3LYP, mPW1PW91, and M06–2X at 6–311++G(d,p) basis set. After all these characterizations, the antioxidant activity was studied using the reaction with the compound DPPH in methanol solution and the mechanism was investigated theoretically. All the three DFT methods used can describe with great accuracy the PAAPFBA chalcone: the results of infrared spectroscopy and the 1H and 13C isotropic shielding demonstrate to be in excellent agreement with the experimental data. The nonlinear optical (NLO) properties show that the title chalcone can be used with great potential in NLO devices and this result is in good agreement with the Natural Bond Orbital (NBO) analysis, which shows how the electronic density is delocalized within the molecule. Finally, the experimental data of the antioxidant activity showed a moderate rate of reaction with the DPPH molecule (50.92%) and this fact was proved by the theoretical mechanisms with the Hydrogen Atom Transfer (HAT) mechanism more favorable.
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- 2020
14. SAM of gliotoxin on gold: a natural product platform for sugar recognition based on the immobilization of Canavalia brasiliensis lectin (ConBr)
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Thiago T. Silva, Bárbara S. F. Rodrigues, Francisco W.Q. Almeida-Neto, Marcos Vinícius A. Queirós, Mayara N.V. Sousa, Ticyano P. de Sousa, Maria da Conceição F. de Oliveira, Benildo Sousa Cavada, Kyria S. Nascimento, Tércio de F. Paulo, Caio B. Castro, Marcia L. A. Temperini, Izaura C.N. Diógenes, and Dieric S. Abreu
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chemistry.chemical_classification ,biology ,Gliotoxin ,Hydrogen bond ,Stereochemistry ,Chemistry ,General Chemical Engineering ,Self-assembled monolayer ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Adsorption ,Concanavalin A ,Desorption ,Polymer chemistry ,Electrochemistry ,biology.protein ,Thiol ,Molecule ,0210 nano-technology ,PRODUTOS NATURAIS - Abstract
We report the successful fabrication of a novel gold surface coated with a thiol-lectin multilayer that showed specific interaction towards D-mannose sugars. Firstly, the gold surface was spontaneously modified with gliotoxin (gtx), a sulfur containing diketopiperazine isolated from marine-derived fungus, and fully characterized by electrochemical, EIS, SPR and SERS techniques. The results indicated the sulfur bridge of gtx is broken upon adsorption and the molecules are flat lying on gold with surface coverage of 2.3 × 10 −10 mol cm −2 and reductive desorption potential of −0.87 V vs Ag/AgCl, i.e. strongly chemisorbed on gold. The real-time monitoring of the immobilization of Concanavalin Br (ConBr) lectin (6.9 × 10 −12 mol cm −2 ) on the gold surface modified with gliotoxin (Au/gtx) was performed by SPR which was also used to prove the recognition capability of ConBr towards D-mannose remains active on Au/gtx. Comparative studies using 11-mercaptoundecanoic acid and cysteine on gold show the interaction between the thiol layer with ConBr involves a network of hydrogen bonds and that the SAM formed with gliotoxin is the most robust monolayer. Impedimetric measurements in solution containing [Fe(CN) 6 ] 3−/4− redox probe and D-mannose sugar at different concentrations indicate hydrogen bonds are the major intermolecular contributions connecting the sugar molecules to the sugar recognition sites of ConBr where Ca 2+ and Mn 2+ ions are inserted..
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- 2017
15. Structural, electronic, and optical properties of inhomogeneous Ca1−xMg x O alloys
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Valder N. Freire, Pedro de Lima-Neto, Francisco W.Q. Almeida-Neto, J. S. de Sousa, G. Santos-Castro, M. B. da Silva, and E. W. S. Caetano
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010302 applied physics ,Diffraction ,Materials science ,Band gap ,Analytical chemistry ,General Physics and Astronomy ,02 engineering and technology ,Crystal structure ,Dielectric ,021001 nanoscience & nanotechnology ,Mole fraction ,01 natural sciences ,0103 physical sciences ,X-ray crystallography ,Density functional theory ,Crystallite ,0210 nano-technology - Abstract
The structural, electronic, and optical properties of homogeneous and inhomogeneous Ca 1 − x Mg x O alloys are studied with the density functional theory (DFT) under the assumption of polymorphism. Large supercells ( 2 × 2 × 2 and above) with different lattice symmetries and varying Mg molar fraction x were constructed, representing distinct solid phases that may coexist in micro/nanodomains of inhomogeneous alloys. We demonstrate that these polymorphs exhibit rich phenomenology like similar formation enthalpies for a given concentration x, but different electronic and optical properties. For example, Ca 0.5 Mg 0.5 O may have crystallites with four possible lattice symmetries using a 2 × 2 × 2 supercell for its description, with bandgaps varying between 3.26 eV (direct) and 4.46 eV (indirect). The DFT-simulated X-ray diffraction shows that polymorphism causes broadening and shift of the diffraction peaks. We also performed a detailed calculation of the bandgaps, optical absorption, and dielectric constants as a function of x for each polymorph, and they exhibit a structured bandgap behavior with maxima and minima in the 0.0 < x < 1.0 range, which is in marked contrast to Vegard’s law rule of mixtures. We also report a direct-to-indirect bandgap transition occurring between 0.072 ≤ x ≤ 0.1094 for the F M 3 ¯ M symmetry.
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- 2019
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