Synthesis and evaluation of photophysical, electrochemical, and ROS generation properties of new chalcogen-naphthoquinones-1,2,3-triazole hybrids

This study presents a comprehensive analysis encompassing the synthesis, structural elucidation, photophysical behavior, and electrochemical properties of a novel series of chalcogen-naphthoquinone-1,2,3-triazole hybrids. Employing a meticulously designed protocol, the synthesis of these hybrids, denoted as 11a-j, was achieved with remarkable efficiency (yielding up to 81%). This synthesis used a regioselective copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC). Furthermore, a detailed investigation into the photophysical characteristics, TDDFT calculations, electrochemical profiles, and photobiological attributes of compounds 11a-j was conducted. This exploration aimed to unravel insights into the excited state behaviors of these molecules, as well as their redox properties. Such insights are crucial for future applications of these derivatives in diverse biological assays.

Green Approach for the Synthesis of Chalcogenyl- 2,3-dihydrobenzofuran Derivatives Through Allyl-phenols/ Naphthols and Their Potential as MAO-B Inhibitors

This work presents the design, synthesis, and MAO-B inhibitor activity of a series of chalcogenyl-2,3-dihydrobenzofurans derivatives. Using solvent- and metal-free methodology, a series of chalcogen-containing dihydrobenzofurans 7-9 was obtained with yields ranging from 40% to 99%, using an I2 /DMSO catalytic system. All compounds were fully structurally characterized using 1 H and 13 C NMR analysis, and the unprecedented compounds were additionally analyzed using high-resolution mass spectrometry (HRMS). In addition, the mechanistic proposal that iodide is the most likely species to act in the transfer of protons along the reaction path was studied through theoretical calculations. Finally, the compounds 7b-e, 8a-e, and 9a showed great promise as inhibitors against MAO-B activity.

Younger Researchers of the Brazilian Chemical Society: a network fostering representation, communication, and collaboration

The Younger Researchers of the Brazilian Chemical Society committee supports early career researchers promoting communication, collaboration, education, networking, representation, and career development.

Demonstrating the interference of tissue processing in the evaluation of tissue biomarkers: The case of PD-L1

The immunohistochemical (IHC) expression of PD-L1 in cancer models is used as a predictive biomarker of response to immunotherapy. We aimed to evaluate the impact of the usage of 3 different tissue processors in the IHC expression of PD-L1 antibody clones: 22C3 and SP142. Three different topographies of samples (n = 73) were selected at the macroscopy room: 39 uterine leiomyomas, 17 placentas and 17 palatine tonsils. Three fragments were collected from each sample and were inked with a specific color that represented their separate processing in a different tissue processor (A, B or C). During embedding, the 3 fragments with distinct processing were ensemble in the same cassette for sectioning of 3 slides/each: hematoxylin-eosin, 22C3 PDL1 IHC staining and SP142 PD-L1 IHC staining, that were blindly observed by 2 pathologists under digital environment. All but one set of 3 fragments were considered adequate for observation even in the presence of artifacts associated with processing issues that were recorded as high as 50.7 % for processor C. The occurrence of background non-specific staining and the presence of false positive results appear to be unrelated with the PD-L1 clone or the type of tissue processing. 22C3 PD-L1 was more frequently considered adequate for evaluation than SP142 PD-L1 that, in 29.2 % of WSIs (after tissue processor C) were considered not adequate for observation due to lack of the typical pattern of expression. Similarly, the intensity of PD-L1 staining was significantly decreased in fragments processed by C (both PD-L1 clones) in tonsil and placenta specimens, and by A (both clones) in comparison with those processed by B. This study demonstrates the need to standardize the tissue processing in pathology to cope with the growing needs of precision medicine quantifications and the production of high-quality material necessary for computational pathology usage.

Ecofriendly aminochalcogenation of alkenes: a green alternative to obtain compounds with potential anti SARS-CoV-2 activity

Here, we report a solvent- and metal-free methodology for the aminochalcogenation of styrenes, using molecular iodine as a catalyst, DMSO as a stoichiometric oxidant, and different nucleophiles under microwave irradiation....

Seleno- and Telluro-Functionalization of Quinones: Molecules with Relevant Biological Application

Quinones and organochalcogens are classes of compounds with great biological applicability, such as antioxidant, anticancer, anti-Alzheimer, and antidepressant activities, among others. Thus, the combination of these two classes of compounds is important to obtain new hits with biological activities that are additive or synergistic. Several methodologies for the preparation of this class of hybrid compound have been widely described. Many of the prepared hybrid molecules have shown increased biological activities and, in some cases, to act as two distinct pharmacophores. In this review, methods for the preparation of selenium-quinones, tellurium-quinones and their biological applications are highlighted.

The Effect of Diabetes and Prediabetes on Mycobacterium tuberculosis Transmission to Close Contacts

BACKGROUND

It is unknown whether dysglycemia is associated with Mycobacterium tuberculosis transmission.

METHODS

We assessed epidemiological and clinical characteristics of patients with culture-confirmed pulmonary tuberculosis and their close contacts, enrolled in a multicenter prospective cohort in Brazil. Contacts were investigated at baseline and 6 months after enrollment. QuantiFERON positivity at baseline and conversion (from negative to positive at month 6) were compared between subgroups of contacts according to glycemic status of persons with tuberculosis (PWTB) as diabetes mellitus (DM) or prediabetes. Multivariable mixed-effects logistic regression models were performed to test independent associations with baseline QuantiFERON positive and QuantiFERON conversion.

RESULTS

There were 592 PWTB (153 DM, 141 prediabetes, 211 normoglycemic) and 1784 contacts, of whom 658 were QuantiFERON-positive at baseline and 106 converters. Multivariable analyses demonstrated that tuberculosis-prediabetes cases, acid-fast bacilli-positive, pulmonary cavities, and living with someone who smoked were independently associated with QuantiFERON positive in contacts at baseline. DM, persistent cough, acid-fast bacilli-positive, and pulmonary cavities in tuberculosis source cases were associated with QuantiFERON conversion.

CONCLUSIONS

Contacts of persons with pulmonary tuberculosis and dysglycemia were at increased risk of being QuantiFERON positive at baseline or month 6. Increased focus on such close contacts could improve tuberculosis control.

Tuberculosis Burden and Determinants of Treatment Outcomes According to Age in Brazil: A Nationwide Study of 896,314 Cases Reported Between 2010 and 2019

Approximately 1.4 million people die annually worldwide from tuberculosis. Large epidemiologic studies can identify determinants of unfavorable clinical outcomes according to age, which can guide public health policy implementation and clinical management to improve outcomes. We obtained data from the national tuberculosis case registry; data were reported to the Brazilian National Program (SINAN) between 2010 and 2019. Clinical and epidemiologic variables were compared between age groups (child: <10 years, young: 10–24years, adult: 25–64years, and elderly: ≥65years). Univariate comparisons were performed together with second-generation p-values. We applied a backward stepwise multivariable logistic regression model to identify characteristics in each age group associated with unfavorable TB treatment outcomes. There were 896,314 tuberculosis cases reported during the period. Tuberculosis incidence was highest among adult males, but the young males presented the highest growth rate during the period. Directly observed therapy (DOT) was associated with protection against unfavorable outcomes in all age groups. The use of alcohol, illicit drugs, and smoking, as well as occurrence of comorbidities, were significantly different between age groups. Lack of DOT, previous tuberculosis, race, location of tuberculosis disease, and HIV infection were independent risk factors for unfavorable outcome depending on the age group. The clinical and epidemiological risk factors for unfavorable tuberculosis treatment outcomes varied according to age in Brazil. DOT was associated with improved outcomes in all age groups. Incidence according to age and sex identified adults and young males as the groups that need prevention efforts. This supports implementation of DOT in all populations to improve tuberculosis outcomes.

Supramolecular kinetic effects by pillararenes: the synergism between spatiotemporal and preorganization concepts in decarboxylation reactions

Spatiotemporal and preorganization factors were both responsible for the catalytic and inhibitory supramolecular effects in decarboxylation reactions.

Anti-tubercular profile of new selenium-menadione conjugates against Mycobacterium tuberculosis H37Rv (ATCC 27294) strain and multidrug-resistant clinical isolates

Tuberculosis (TB) is one of the most fatal diseases and is responsible for the infection of millions of people around the world. Most recently, scientific frontiers have been engaged to develop new drugs that can overcome drug-resistant TB. Following this direction, using a designed scaffold based on the combination of two separate pharmacophoric groups, a series of menadione-derived selenoesters was developed with good yields. All products were evaluated for their in vitro activity against Mycobacterium tuberculosis H37Rv and attractive results were observed, especially for the compounds 8a, 8c and 8f (MICs 2.1, 8.0 and 8.1 μM, respectively). In addition, 8a, 8c and 8f demonstrated potent in vitro activity against multidrug-resistant clinical isolates (CDCT-16 and CDCT-27) with promising MIC values ranging from 0.8 to 3.1 μM. Importantly, compounds 8a and 8c were found to be non-toxic against the Vero cell line. The SI value of 8a (>23.8) was found to be comparable to that of isoniazid (>22.7), which suggests the possibility of carrying out advanced studies on this derivative. Therefore, these menadione-derived selenoesters obtained as hybrid compounds represent promising new anti-tubercular agents to overcome TB multidrug resistance.

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New menadione-derived selenoesters were synthesized.

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The compounds demonstrated excellent activity against M. tuberculosis H37Rv.

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8a, 8c and 8f showed potent activity against multidrug resistant clinical isolates.

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Compounds 8a and 8c were found to be non-toxic.

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These organoselenium compounds represent promising new anti-tubercular agents.

Fast and easy conversion of ortho amidoaryldiselenides into the corresponding ebselen-like derivatives driven by theoretical investigations

The in silico predicted Se⋯N interaction on amidoarylselenenyl iodides has been experimentally exploited for the efficient synthesis of N-substituted benzoisoselenazol-3(2H)-ones, benzoisothiazol-3(2H)-ones and ebselen, recently reported as potent antiviral agent against Sars-Cov2.

Molecular recognition of methamphetamine by carboxylatopillar[5]arene: drug-dependent complexation stoichiometry and insights into medical applications

The molecular recognition of the carboxylatopillar[5]arene on methamphetamine showed interconversion between H₂:G ⇋ H:G stoichiometries with dependence on drug concentration.

A reversible, switchable pH-driven quaternary ammonium pillar[5]arene nanogate for mesoporous silica nanoparticles

Here we describe the assembly and pH-driven operation of two nanocarriers based on non-functionalized (MCM-41) and carboxylate-functionalized (MCM-41-COOH) containers loaded with the anticancer drug doxorubicin (DOX) and capped by quaternary ammonium pillar[5]arene (P[5]A) nanogates. MCM-41 and MCM-41-COOH containers were synthesized and transmission and scanning electron microscopies showed nanoparticles with spherical morphology and dimensions of 85 ± 13 nm. The nanochannels of MCM-41 loaded with DOX were gated through the electrostatic interactions between P[5]A and the silanolate groups formed at the silica-water interface, yielding the MCM-41-DOX-P[5]A nanocarrier. The second nanocarrier was gated through the electrostatic interactions between the carboxylate groups mounted on the surface of MCM-41 and P[5]A, resulting in the MCM-41-COO-DOX-P[5]A nanocarrier. The DOX release profiles from both nanocarriers were investigated by UV-vis spectroscopy at different pH values (2.0, 5.5 and 7.4) and also in the presence of ions, such as citrate^3- (19 mmol L^-1) and Zn²⁺ (1.2 and 50 mmol L^-1) at 37 °C. MCM-41-COO-DOX-P[5]A can be turned on and off eight times through the formation and breaking of electrostatic interactions. In vitro studies show that MCM-41-COO-DOX-P[5]A can penetrate and release DOX in the nucleus of human breast adenocarcinoma MCF-7 cancer cells leading to a pronounced cytotoxic effect. Therefore, the fabricated nanocarrier based on a water-soluble cationic pillar[5]arene nanogate, which is reversibly opened and closed by electrostatic interactions, can be considered as a promising drug transport and delivery technique for future cancer therapy.

Inhibitory and Cooperative Effects Regulated by pH in Host-Guest Complexation between Cationic Pillar[5]arene and Reactive 2-Carboxyphthalanilic Acid

The study of host-guest complexation between reactive 2-carboxyphthalanilic acid (CPA) and two cationic pillararenes has been carried out. Host-guest complexation with significant kinetic effects was observed only with the smaller cavity size pillararene (P5A). Kinetics in the pH range 1.50-6.40, ESI-MS, ¹H NMR titration, and ROESY experiments were performed to characterize the complexes. High binding stoichiometry (H:G₂) was observed for all CPA protonation states. The system is pH-dependent, and inversion of cooperativity (negative to positive) occurs by increasing the dianionic CPA^2- concentration (allosteric behavior). Toward physiological pH, association constant K_1:1 does not change (10⁴ M^-1), and K_1:2 increased from 10² to 10⁴ M^-1, as well as the inhibitory effect increased up to 222-fold. NMR results elucidated the structure of the complex and allowed us to create a map of H-H interactions that describes well the diversity and number of interactions in the complex.

Establishment and cryptic transmission of Zika virus in Brazil and the Americas

Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 2016) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 2016). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.

DENSIDADE DE PLANTAS E FONTES DE NITROGÊNIO NO CULTIVO DE FEIJOEIRO

O nitrogênio (N) é o nutriente absorvido em maior quantidade e sua dinâmica é complexa no sistema solo-planta, além disso, a densidade de plantas em cultivo de feijão “de inverno” é variável em diversas condições edafoclimáticas, necessitando de informações mais consistentes. Diante disso, este trabalho teve como objetivo quantificar qual a melhorfontes de Nem cobertura e densidades de plantasidealno crescimento e produtividade do feijão “de inverno” nopreparoconvencional do soloem um ArgissoloVermelho Amarelo. O trabalho foi desenvolvido no município de Fernandópolis, SP, na época de outono-inverno da safra 2014, em um Argissolo Vermelho Amarelo detextura arenosa, em umdelineamento experimental em blocos casualizados disposto em um esquema fatorial 4x3, comquatro repetições. Os tratamentos foramconstituídos pela combinação de quatrofontes de N(ausência de N, ureia convencional, sulfato de amôniae mistura (50% N sulfato de amônio + 50%N ureia)) com três densidades de plantas (4, 6 e 8 plantas por metro linear). A aplicação das fontes de N sulfato de amônio e a misturaem cobertura no feijão“de inverno”com à densidade de 4 plantas metro linear, proporcionaram incrementos na massa de matéria seca e no número de vagens planta-1do feijoeiro. Na ausência de N em cobertura houveredução dadensidades de plantas eprodutividade de grãos do feijão. As três fontes de Nem cobertura na densidade de 8 plantas por metro linear resultaram em incrementos emprodutividades de grãos no feijoeiro.

Diphenyl diselenide derivatives inhibit microbial biofilm formation involved in wound infection

Background

Organoselenium compounds have antimicrobial activity against some bacteria and fungi; furthermore, the antioxidant activity of diselenides has been demonstrated. The aim of the present work was to examine the in vitro minimal inhibitory concentration of a panel of differently substituted diselenides and their effectiveness in inhibiting biofilm formation and dispersing preformed microbial biofilm of Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus pyogenes and Pseudomonas aeruginosa and the yeast Candida albicans, all involved in wound infections. Moreover, the cytotoxicity of the compounds was determined in human dermal fibroblast and keratinocytes. In closing, we tested their direct antioxidant activity.

Results

Diselenides showed different antimicrobial activity, depending on the microorganism. All diselenides demonstrated a good antibiofilm activity against S. aureus and S. epidermidis, the compounds camphor diselenide, bis[ethyl-N-(2’-selenobenzoyl) glycinate] and bis[2’-seleno-N-(1-methyl-2-phenylethyl) benzamide] were active against S. pyogenes and C. albicans biofilm while only diselenides 2,2’-diselenidyldibenzoic acid and bis[ethyl-N-(2’-selenobenzoyl) glycinate] were effective against P. aeruginosa. Moreover, the compounds bis[ethyl-N-(2’-selenobenzoyl) glycinate] and bis[2’-seleno-N-(1-methyl-2-phenylethyl) benzamide] showed an antioxidant activity at concentrations lower than the 50 % of cytotoxic concentration.

Conclusions

Because microbial biofilms are implicated in chronic infection of wounds and treatment failure, the combination of antimicrobial activity and potential radical scavenging effects may contribute to the improvement of wound healing. Therefore, this study suggests that bis[ethylN-(2’-selenobenzoyl) glycinate] and bis[2’-seleno-N-(1-methyl-2-phenylethyl) benzamide] are promising compounds to be used in preventing and treating microbial wound infections.

FONTES E MODOS DE APLICAÇÃO DE NITROGÊNIO NA CULTURA DO MILHO EM SISTEMA PLANTIO DIRETO

O milho é uma das culturas mais exigentes em fertilizantes, especialmente os nitrogenados. Com isso o presente trabalho teve como objetivo avaliar, em solo de cerrado, o efeito de fontes e modos de aplicação de nitrogênio (N) com e sem incorporação pela água de irrigação, na cultura do milho em sistema plantio direto. O experimento foi conduzido em Latossolo vermelho distrófico argiloso. O delineamento experimental foi em blocos casualizados com 12 tratamentos dispostos em esquema fatorial 3x2x2, com quatro repetições. Os tratamentos foram constituídos por duas fontes de N (ureia, nitrato de amônio e testemunha – sem N), dois modos de aplicação (a lanço e em faixas) com ou sem a incorporação pela lâmina dede irrigação de 10 mm. Foram avaliadas: a massa de cem grãos e a produtividade de grãos (kg ha-1). Pode-se concluir que houve efeito da adubação nitrogenada, sendo que nitrato de amônio proporcionou a maior produtividade de grãos. Em relação aos modos de aplicação, quando a adubação foi realizada a lanço obteve-se a maior produtividade de grãos. Já a incorporação do N com lâmina de irrigação de 10 mm, embora tenha influenciado a massa dos grãos, não incrementou a produtividade de grãos de milho.

DOSES DE NITROGÊNIO NO FEIJÃO DE INVERNO EM SUCESSÃO À GRAMÍNEAS COM E SEM INOCULAÇÃO DE Azospirillum brasilense:ANÁLISE ECONÔMICA

Nos sistemas produtivos, o nitrogênio é um dos nutrientes mais absorvidos e importantes para o feijoeiro, por outro lado, é o nutriente aplicado em maior quantidade sendo assim o que mais onera no custo de produção da leguminosa. Com isso o presente trabalho teve como objetivo avaliar a viabilidade econômica de doses de nitrogênio em cobertura na produtividade de grãos do feijoeiro de inverno, cultivado em sistema plantio direto, após diferentes culturas. O experimento foi instalado em área experimental pertencente à Faculdade de Engenharia – UNESP, Câmpus de Ilha Solteira, no município de Selvíria (MS), com altitude de 335 metros. O solo do local é do tipo Latossolo Vermelho Distrófico argiloso (EMBRAPA, 2006). O delineamento experimental utilizado foi o de blocos casualizados com 16 tratamentos dispostos em esquema fatorial 4x4 com quatro repetições. Os tratamentos foram constituídos por quatro coberturas vegetais (milho e/ou Urochloa ruziziensis inoculados ou não com Azospirillum brasilense) e doses de nitrogênio em cobertura (0, 40, 80 e 120 kg ha-1). As parcelas foram constituídas por uma área de 7 linhas (espaçamento de 0,45 m) de milho com 5 m de comprimento. A análise econômica foi realizada de acordo a técnica da orçamentação parcial, detalhada em Noronha (1987). Recomenda-se para obtenção de maior acréscimo de produtividade de grãos e maior margem de ganho do feijão de inverno irrigado por aspersão em plantio direto a aplicação de 80 kg ha-1 de nitrogênio em cobertura no feijão em sucessão ao milho solteiro com a inoculação de Azospirillum brasilense.

Design, synthesis and evaluation of seleno-dihydropyrimidinones as potential multi-targeted therapeutics for Alzheimer's disease

We report the design, synthesis and evaluation of a series of seleno-dihydropyrimidinones as potential multi-targeted therapeutics for Alzheimer's disease.

“The green side of the moon: ecofriendly aspects of organoselenium chemistry”

Key aspects for the development of a greener synthesis and the use of the organoselenium compounds.