A consensus reverse docking approach for identification of a competitive inhibitor of acetyltransferase enhanced intracellular survival protein from Mycobacterium tuberculosis.

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb), which remains a significant global health challenge. The emergence of multidrug-resistant (MDR) Mtb strains imposes the development of new therapeutic strategies. This study focuses on the identification and evaluation of potential inhibitors against Mtb H37Ra through a comprehensive screening of an in-house chemolibrary. Subsequently, a promising pyrimidine derivative (LQM495) was identified as promising and then further investigated by experimental and in silico approaches. In this context, computational techniques were used to elucidate the potential molecular target underlying the inhibitory action of LQM495. Then, a consensus reverse docking (CRD) protocol was used to investigate the interactions between this compound and several Mtb targets. Out of 98 Mtb targets investigated, the enhanced intracellular survival (Eis) protein emerged as a target for LQM495. To gain insights into the stability of the LQM495-Eis complex, molecular dynamics (MD) simulations were conducted over a 400 ns trajectory. Further insights into its binding modes within the Eis binding site were obtained through a Quantum mechanics (QM) approach, using density functional theory (DFT), with B3LYP/D3 basis set. These calculations shed light on the electronic properties and reactivity of LQM495. Subsequently, inhibition assays and kinetic studies of the Eis activity were used to investigate the activity of LQM495. Then, an IC50 value of 11.0 ± 1.4 µM was found for LQM495 upon Eis protein. Additionally, its Vmax, Km, and Ki parameters indicated that it is a competitive inhibitor. Lastly, this study presents LQM495 as a promising inhibitor of Mtb Eis protein, which could be further explored for developing novel anti-TB drugs in the future.

Design, synthesis, antiviral evaluation, and In silico studies of acrylamides targeting nsP2 from Chikungunya virus.

The Togaviridae family comprises several New- and Old-World Alphaviruses that have been responsible for thousands of human illnesses, including the RNA arbovirus Chikungunya virus (CHIKV). Firstly, it was reported in Tanzania in 1952 but rapidly it spread to several countries from Europe, Asia, and the Americas. Since then, CHIKV has been circulating in diverse countries around the world, leading to increased morbidity rates. Currently, there are no FDA-approved drugs or licensed vaccines to specifically treat CHIKV infections. Thus, there is a lack of alternatives to fight against this viral disease, making it an unmet need. Structurally, CHIKV is composed of five structural proteins (E3, E2, E1, C, and 6k) and four non-structural proteins (nsP1-4), in which nsP2 represents an attractive antiviral target for designing novel inhibitors since it has an essential role in the virus replication and transcription. Herein, we used a rational drug design strategy to select some acrylamide derivatives to be synthesized and evaluated against CHIKV nsP2 and also screened on CHIKV-infected cells. Thus, two regions of modifications were considered for these types of inhibitors, based on a previous study of our group, generating 1560 possible inhibitors. Then, the 24 most promising ones were synthesized and screened by using a FRET-based enzymatic assay protocol targeting CHIKV nsP2, identifying LQM330, 333, 336, and 338 as the most potent inhibitors, with Ki values of 48.6 ± 2.8, 92.3 ± 1.4, 2.3 ± 1.5, and 181.8 ± 2.5 µM, respectively. Still, their Km and Vmax kinetic parameters were also determined, along with their competitive binding modes of CHIKV nsP2 inhibition. Then, ITC analyses revealed KD values of 127, 159, 198, and 218 µM for LQM330, 333, 336, and 338, respectively. Also, their ΔH, ΔS, and ΔG physicochemical parameters were determined. MD simulations demonstrated that these inhibitors present a stable binding mode with nsP2, interacting with important residues of this protease, according to docking analyzes. Moreover, MM/PBSA calculations displayed that van der Waals interactions are mainly responsible for stabilizing the inhibitor-nsP2 complex, and their binding energies corroborated with their Ki values, having -198.7 ± 15.68, -124.8 ± 17.27, -247.4 ± 23.78, and -100.6 ± 19.21 kcal/mol for LQM330, 333, 336, and 338, respectively. Since Sindbis (SINV) nsP2 is similar to CHIKV nsP2, these best inhibitors were screened against SINV-infected cells, and it was verified that LQM330 presented the best result, with an EC50 value of 0.95 ± 0.09 µM. Even at 50 µM concentration, LQM338 was found to be cytotoxic on Vero cells after 48 h. Then, LQM330, 333, and 336 were evaluated against CHIKV-infected cells in antiviral assays, in which LQM330 was found to be the most promising antiviral candidate in this study, exhibiting an EC50 value of 5.2 ± 0.52 µM and SI of 31.78. The intracellular flow cytometry demonstrated that LQM330 is able to reduce the CHIKV cytopathogenic effect on cells, and also reduce the percentage of CHIKV-positive cells from 66.1% ± 7.05 to 35.8% ± 5.78 at 50 µM concentration. Finally, qPCR studies demonstrated that LQM330 was capable of reducing the number of viral RNA copies/µL, suggesting that CHIKV nsP2 is targeted by this inhibitor as its mechanism of action.

Influence of phenolic compounds on color formation at different stages of the VHP sugar manufacturing process.

Phenolic compounds are natural dyes contained in sugarcane juice and represent an important parameter in industrial processing, as they significantly affect the color formation of raw sugar. This study investigated the relationship between color formation and phenolic compounds during a Very High Polarization (VHP) sugar manufacturing process, in which the RB92579 genotype represents about 50% of the processed sugarcane. The products evaluated during the industrial processing of sugarcane were: raw juice, mixed juice, lime-treated juice, clarified juice, syrup, massecuite, and VHP sugar. The polyphenols catechin (CAT), chlorogenic acid (CGA), caffeic acid (CAF), vanillin (VAN), syringaldehyde (SYR), p-coumaric acid (p-COU), coumarin (CUM), and rutin (RUT) were quantified by high-performance liquid chromatography (HPLC). The highest concentrations of CGA and SYR were obtained from the sucrose crystallization product (massecuite), similarly to the parameters of color, total phenols and the total polyphenol content. CGA was the predominant polyphenol in the samples of clarified juice, syrup, massecuite and VHP sugar, with the latter presenting concentrations above 50%. The presence of phenolic compounds provided different indices of color during the production process. In this context, chlorogenic acid (CGA) was the compound that presented the most expressive results, contributing significantly to the formation of color in sugarcane processing products, which is a fact that has not yet been reported in the literature. The color of the VHP sugar crystals also had a positive relationship with the concentration of phenolics, with greater evidence for CGA.

Consumption of minimally processed food is inversely associated with excess weight in adolescents living in an underdeveloped city.

BACKGROUND: The consumption of ultra-processed foods may be associated with the development of chronic diseases, both in adults and in children/adolescents. This consumption is growing worldwide, especially in low and middle-income countries. Nevertheless, its magnitude in small, poor cities from the countryside is not well characterized, especially in adolescents. This study aimed to assess the consumption of minimally processed, processed and ultra-processed foods by adolescents from a poor Brazilian city and to determine if it was associated with excess weight, high waist circumference and high blood pressure. METHODS: Cross-sectional study, conducted at a public federal school that offers technical education together with high school, located in the city of Murici. Adolescents of both sexes and aged between 14-19 years old were included. Anthropometric characteristics (weight, height, waist circumference), blood pressure, and dietary intake data were assessed. Associations were calculated using Poisson regression models, adjusted by sex and age. RESULTS: At total, 249 adolescents were included, being 55.8% girls, with a mean age of 16 years-old. The consumption of minimally processed foods was inversely associated with excess weight (Adjusted Prevalence Ratio: 0.61, 95% Confidence Interval: [0.39-0.96], P = 0.03). Although the consumption of ultra-processed foods was not associated with excess weight, high blood pressure and high waist circumference, 46.2% of the sample reported eating these products more than weekly. CONCLUSION: Consumption of minimally processed food is inversely associated with excess weight in adolescents. Investments in nutritional education aiming the prevention of chronic diseases associated with the consumption of these foods are necessary.