Resumo em Inglês:

A new phenylpropanoid derivative, named euploic acid (1), was isolated from Euploca procumbens (Mill.) Diane & Hilger, Boraginaceae, along with lithospermic acid B (2), lithospermic acid (3), 9’’-methyl lithospermate (4), and luteolin-7-O-glucoside (5). Compound structures were determined by mass spectrometry (MS), nuclear magnetic resonance (NMR) analysis and comparison with published data. Absolute configuration of 1 was established via electronic circular dichroism (ECD). Anti-inflammatory potential of euploic acid (1) was assessed by measuring its inhibition of cytokine and nitric oxide production in stimulated J774 macrophages. Compound 1 significantly reduced pro-inflammatory mediator production and release by stimulated macrophages at non-cytotoxic concentrations, comparable to the efficacy of dexamethasone. Our findings demonstrate the potential of euploic acid (1) as an effective anti-inflammatory agent. This study contributes to the structural elucidation of a new phenylpropanoid derivative and highlights its promising anti-inflammatory activity in the treatment of inflammatory disorders.

Resumo em Inglês:

In this report, we designed and synthesized ten N-(R-phenyl)-3-carboxamide-coumarin derivatives (2a-2j), exploring the coumarin nucleus, and an R-phenyl group as a structural scaffold and a peptide bond as a linker between them. The structure-activity relationships were investigated with different R-substituents (H, Br, NO2, Cl) in ortho, meta, or para positions from the phenyl group. Coumarins were obtained in good yields (72-95%), and in vitro screening against Canavalia ensiformis urease showed potential inhibitory percentages ranging from 42 to 65%. Half-maximal inhibitory concentration (IC50) values were determined for the best compounds 2b (R = 2-Br) and 2d (R = 4-Br). After conducting molecular docking and molecular dynamics on urease from C. ensiformis and Helicobacter pylori, potential binding modes for the most effective compounds 2b and 2d showed that these derivatives are able to interact with the crucial residue Cys592, thereby blocking the access of the urea substrate to the active site. According to density functional theory (DFT) calculations, 4-Br substitution on H. pylori urease was necessary for interacting with catalytic amino acids on the active site.

Resumo em Inglês:

The aim of the present study was to evaluate the effect of roasting and cocoa mass content on the composition of chocolates. Chocolate formulations were developed (40, 50, 60 and 70% cocoa solids) using unroasted and roasted cocoa beans, and analyses were performed: physicochemical, chemical composition, antioxidant capacity, procyanidin content, total phenolic compounds, quantification of theobromine, caffeine, catechin and epicatechin by high performance liquid chromatography (HPLC) and spectroscopic profile by mid-infrared spectroscopy (MIR). The results revealed that higher values of total phenolics, epicatechin and procyanidins, were obtained in chocolates produced with unroasted cocoa beans, with a significant difference in relation to those with roasted cocoa beans. It was observed that increasing the percentage of cocoa in the formulations caused an increase in the content of bioactive compounds. The use of MIR in the differentiation of chocolate samples produced with roasted and unroasted cocoa beans obtained a positive result. This technique associated with principal component analysis (PCA) enabled the separation of chocolates according to the type of cocoa bean (roasted and unroasted) used in production, confirming its importance for a quick evaluation of the parameters.

Resumo em Inglês:

Development of platforms capable of guarantee a controlled NO release at a specific target is highly promising yet challenging. Herein, we present the synthesis and characterization of cis-[Ru(bpy)2(1,4-dt)(NO)](PF6)3 (RuNO), where 1,4-dt = 1,4-dithiane and bpy = 2,2’-bipyridine, which was adsorbed on gold through the sulfur atom of 1,4-dt. This complex was thoroughly characterized by electrochemistry, nuclear magnetic resonance, and vibrational and electronic spectroscopies whose assignments were corroborated by theoretical data. The formation of the self-assembled monolayer (SAM) of RuNO on gold was monitored by surface plasmon resonance giving a coverage density of 2.1 × 10–10 mol cm–2. Taking advantage of the NO lability upon reduction, electrochemical scanning microscopy (SECM) was used to both trigger the NO release from the SAM of RuNO on the gold substrate and detection at the SECM tip. Accordingly, upon reduction, the generated NO0 species was detected at the SECM TIP, where it was oxidized back to NO+.

Resumo em Inglês:

To investigate the anthropogenic contamination of the Port of Suape, five surface sediments were collected and subjected to a geochemical characterization based on the determination of environmental biomarkers such as sterols, aliphatic and polycyclic aromatic hydrocarbons, and also metals and arsenic. Sterol analyses point to a moderate level of sewage contamination, while n-alkanes analyses indicated contamination by petroleum in an early stage of biodegradation. Polycyclic aromatic hydrocarbons analyses pointed to a mixture of contributions for the organic matter, which were predominantly found for petrogenic and pyrolytic sources. The quantification of trace metals indicated a low risk to the environment, except for As, which was identified as displaying moderate contamination. During the analysis of all biomarkers, the sediment collected near one of the shipyards was the most affected. These results enable comprehension of the level of contamination in an important Brazilian port and the need to develop remediation policies.

Resumo em Inglês:

The aim of this work was to extract and characterize pectin from lyophilized noni pulp (Morinda citrifolia Linn.) at three different pHs using different extractor agents and to evaluate anti-viral activity. The extraction of high yield (acid extraction) was subjected to sulfation procedure. Fourier transform infrared spectroscopy and proton nuclear magneticresonance analysis were used to calculate the degree of methylation of pectin from acid extraction and its sulfated derivative. The data obtained for the degree of methylation of noni pectin and sulfated pectin were 30.3 and 30.7, respectively. Pectin was subjected to acute oral toxicity testing in mice. The results showed that pectin had a pro-inflammatory effect, and sulfated pectin had an anti-inflammatory effect. Both pectins were also evaluated for herpes simplex virus activity in vitro, and although they successfully inhibited virus replication, the sulfated pectins were cytotoxic.

Resumo em Inglês:

Naringenin is a flavonoid with several biological activities already reported but with few biological applications in the pharmaceutical field. In this work, a new flavanone, called carboxymidamide (DCHA), synthesized through the condensation reaction between naringenin and aminoguanidine is structurally confirmed through spectroscopic analysis of nuclear magnetic resonance, mass spectrometry and Fourier transform infrared. DCHA was not toxic to human fibroblasts and inhibited macrophage activation in vitro. In vivo, it suppressed leukocyte migration in lipopolysaccharide (LPS)-induced peritonitis and reduced zymosan-induced paw edema. Molecular docking simulations of DCHA in the active site of the enzymes inducible nitric oxide synthase, cyclooxygenase-2 and phosphodiesterase type 4 indicate that the anti-inflammatory activity of this new flavanone can be explained by the inhibition of these target enzymes. This is the first work to present the synthesis of a flavonoid derivative with aminoguanidine that showed a high anti-inflammatory potential.

Resumo em Inglês:

Olive oil is a highly demanded product renowned for its unique taste and diverse nutrient content, primarily composed of lipids. This study aimed to comprehensively analyze the lipid profiles of four olive varieties (Arbequina, Arbosana, Koroneiki, and Frantoio) and their corresponding commercial olive oils using advanced analytical techniques, namely electrospray ionization mass spectrometry and gas chromatography with flame ionization detector, combined with principal component analysis. The nutritional quality of the olive oils was evaluated based on parameters such as the ratio of saturated acids to polyunsaturated acids, atherogenicity, thrombogenicity, and andhypocholesterolemic/hypercholesterolemic indexes. The study revealed that the primary fatty acids identified were palmitic, stearic, oleic, and linoleic acids, while triolein, palmitodiolein, and stearodiolein emerged as the most abundant triacylglycerol across all samples. Furthermore, the results demonstrated that the commercial olive oil samples exhibited an exceptional nutritional profile. Overall, this study highlights the significance and efficacy of the analytical and statistical techniques employed to unravel the lipid profiles of olive oils, a product of substantial commercial value and susceptible to adulteration. Additionally, it emphasizes the importance of utilizing nutritional quality indices to assess the health benefits associated with olive oil consumption.

Resumo em Inglês:

Indirubin is an isomer of the blue dye indigo. It is widely used in Chinese medicine as part of therapy against many diseases and, thus, its skeleton becomes a promising candidate for new drug prototypes. Since it has low solubility, its properties could be improved through the insertion of hydrophilic and pharmacophoric groups, such as sugars bridged to 1,2,3-triazoles. Here, we report the synthesis of indirubin-based compounds evaluating two different routes: via the aldol condensation reaction of triazole-isatin derivatives with 3-acetoxyindole (pathway A) and reductive coupling of isatin, followed by N-propargylation of indirubin. We also performed reactivity studies guided by density functional theory (DFT) calculations (pathway B). As a demonstration, we simulate interactions with the glycogen synthase kinase 3β enzyme, which is associated with neurodegenerative diseases, through both molecular docking and molecular dynamics simulations.

Resumo em Inglês:

A series of mononuclear lanthanide-based coordination compounds was obtained under mild synthetic conditions and fully characterized. Single-crystal X-ray diffraction reveals six isomorphic compounds of type [Ln(NO3)(4picH)2(H2O)4](NO3)2(Ln3+ = Sm (1), Eu (2), Gd (3), Tb (4), Dy (5), Er (6)), in which 4picH is the zwitterionic form of the 4-picolinic acid. Except for compounds 3and 6, a study into the emissive properties of the compounds was carried out, revealing a ligand-sensitized lanthanide-characteristic luminescence. Compounds 2 and 4are candidates for luminescent probes in solution. At the same time, the chromaticity data for 5 revealed a potential white-light emitter with a correlated color temperature (CCT) value of 6570 K. Alternating current (AC) magnetic susceptibility measurements, supported by theoretical calculations, showed a field-induced slow relaxation of the magnetization and a single-ion magnet behavior for compound 5.

Resumo em Inglês:

A novel electroanalytical approach is presented for the determination of ronidazole in environmental and food matrices by applying a cathodically pretreated boron-doped diamond electrode and the square-wave adsorptive cathodic stripping voltammetry technique. From the studies of cyclic voltammetry to investigate the electroactivity of the ronidazole molecule, the occurrence of an irreversible cathodic process was verifed, which was more effciently detected using the cathodically pretreated boron-doped diamond electrode compared to the anodically pretreated electrode. Still on the electrochemical response of ronidazole, the effects of pH and scan rate were studied and, its apparent diffusion coeffcient was determined by chronoamperometry (8.20 × 10-6cm2s-1). Under optimal experimental conditions, the analytical curve obtained for ronidazole was linear in two concentration ranges (12.70 to 63.40 µmol L-1 and 76.04 to 126.2 µmol L-1), with a limit of detection of 2.55 µmol L-1. For intra- and inter-day repeatabilities, relative standard deviations of only 2.7 and 3.5% were verifed, which demonstrated the stable analytical response of the electrode. Recovery percentages ranging from 96 to 100% were achieved in the analysis of natural water and whole milk samples. Therefore, the proposed electroanalytical method shows satisfactory analytical performance towards ronidazole determination in varied matrice samples.

Resumo em Inglês:

Ammonia contamination in water is a signifcant environmental issue since it is toxic and leads to eutrophication. Photocatalysis has been investigated as a strategy for ammonia degradation but can potentially form toxic nitrite (NO2–) and nitrate (NO3–) byproducts. This work reports on the ability of niobium oxide (Nb2O5) to photocatalytically oxidize aqueous-phase ammonia (NH3). Whereas as-synthesized Nb2O5 showed little catalytic activity (< 1% NH3 conversion after 6 h of UV-C irradiation, at room temperature and atmospheric pressure, and under O2 headspace), Nb2O5 treated in basic solution (OH-Nb2O5) was able to photocatalytically degrade NH3 at ca. 9% conversion after six hours, with ca. 70% selectivity to the desired N2, with a frst-order rate constant of ca. 12 times higher than the as synthesize catalyst (1.6 × 10–3 min–1 vs. 2.0 × 10–2 min–1). Raman spectroscopic analysis indicated the presence of terminal Nb=O species after base treatment of Nb2O5, implicating them as catalytically active sites. These results underscore how a simple structural modifcation can signifcantly affect photocatalytic activity for aqueous ammonia oxidation.

Resumo em Inglês:

Dry decomposition, wet digestion, and dissolution in aqueous medium for direct analysis were evaluated for the preparation of eight samples of liquid and bar soap and one powder detergent for later determination of Cd, Mg, Pb, and Zn by inductively coupled plasma optical emission spectroscopy (ICP OES). The evaluation of the best conditions for digestion of the samples were chosen from a set of tests where conventional heating using 1 mol L-1 HNO3 with addition of 30% H2O2 proved to be the most effcient method. The average hydrodynamic diameter of 525 nm was determined using dynamic light scattering measurements. The concentrations found were: Cd and Pb (< limit of detection (LOD)), Mg (50.89 to 1119 μg g 1), and Zn (280.25 to 537.54 μg g 1). After evaluating the sample preparation methods, the accuracy of the methodology was verifed through recovery tests of analytes, obtaining values between 83 and 119% and a relative standard deviation (RSD) ≤ 4.30% (n = 6; 4 mg L 1). The LOD ranged from 0.015 to 0.5 µg g 1 and the limits of quantifcation (LOQ) from 0.045 to 2 µg g 1. The soaps and powder detergent samples studied here may be used without any harm to health as the contents were within the limits established by the legislation.

Resumo em Inglês:

As an oral Janus kinase 1 inhibitor, upadacitinib shows good activity in the treatment of rheumatoid arthritis, especially for other drug-resistant and refractory rheumatoid arthritis patients. A key step in the synthesis of upadacitinib is the introduction of ethyl on the pyrroline ring. Here, a FeCl3/p-aminophenol catalyst system was used to increase the ethyl introduction for synthesis of pyrroline building blocks of upadaticinib. This catalytic system allows milder reaction conditions and increases the yield of this step by 25% compared to the existing reports, and the scale-up experiment is still effective. In addition, a possible FeII/FeIV catalytic mechanism for this reaction was also proposed.

Resumo em Inglês:

Three-dimensional structures of proteins are intimately linked to their functions, therefore understanding their conformation in solution is essential. While nuclear magnetic resonance spectroscopy and X-ray crystallography are widely employed for protein structural determination, their limitations make the process challenging and expensive. Theoretical calculations of chemical shifts present a potential complement to experimental techniques, facilitating the study of protein structures. This investigation aims to assess the applicability of chemical shift calculations in analyzing three-dimensional structures of peptides, focusing on the tryptophan zipper 1 peptide as a model. Furthermore, a mutated variant of this peptide was proposed to evaluate the stability of its structural elements under sequence modifcations. Through calculations, a potential structural alteration in the β-turn region of the mutant peptide compared to tryptophan zipper 1 was identifed. This research demonstrates the potential of using computational approaches to complement experimental methods in studying protein structures and their functional implications.

Resumo em Inglês:

The tricarboxylic acid (TCA) cycle is responsible for the generation of energy in the human body and may inform about the energy status in different physiological and pathological conditions. It was developed a method to quantify the TCA cycle intermediates (α-ketoglutaric, citric, fumaric, lactic, malic, and succinic acids) by capillary zone electrophoresis with diode array detector (CZE-DAD) in indirect mode. The background electrolyte consisted of 24 mmol L–1 2,6-pyridine carboxylic acid, 76 mmol L–1 β-alanine, and 4 mmol L–1 hexadecyltrimethylammonium hydroxide (pH 4). The method was validated and presented a good linearity (R2 < 0.9922) and adequate limits of detection (0.24-1.84 mg L–1) and quantifcation (0.74-5.57 mg L–1). The method was successfully applied to samples of individuals with obesity before being submitted to bariatric surgery and one year after the surgery. The citric, lactic, and malic acids were detected in the analyzed samples. To evaluate the changes in concentrations of the TCA intermediates, principal component analysis was carried out, and there was no signifcant difference between the two sets of samples. Altogether, the data obtained after applying this new method suggest that CZE-DAD could be used to detect and quantify the TCA cycle metabolites in human urine.

Resumo em Inglês:

A series of 4H-pyran derivatives were synthesized through a three-component condensation reaction in a pot using aromatic aldehyde, cyclohexanedione, and malononitrile in the dodecyl benzenesulfonic acid/H2O microemulsion system. This protocol is attractive because dodecyl benzenesulfonic acid microemulsion is superior for organic reaction due to its dual catalysis. On the one hand, dodecyl benzenesulfonic acid acts as a Brønsted acid to catalyze the reaction; on the other hand, it can form a microemulsion as surfactant to enlarge the boundary area and entrap water produced during esterification reaction. In addition, the reaction process is simple, with high liaison formation effciency, good yields, and environmentally harmless reaction conditions. The dodecyl benzenesulfonic acid/H2O microemulsion system was equally effective when used in consecutive reactions.