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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.

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

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.

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.

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.

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.

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.

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.

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..