RESUMO

In this study, six analogs of 2-arylquinoline were synthesized and evaluated for their in vitro and in vivo antiplasmodial and leishmanicidal activity. At a later stage, hemolytic activity and druggability were tested in vitro and in silico, respectively, observing as a result: firstly, compounds showed half-maximal effective concentration (EC50) values between 3.6 and 19.3 µM. Likewise, a treatment using the compounds 4a-f caused improvement in most of the treated hamsters and cured some of them. Regarding the antiplasmodial activity, the compounds showed moderate to high activity, although they did not show hemolytic activity. Furthermore, 4e and 4f compounds were not able to control P. berghei infection when administered to animal models. Molecular dynamic simulations, molecular docking and ligand binding affinity indicate good characteristics of the studied compounds, which are expected to be active. And lastly, the compounds are absorbable at the hematoencephalic barrier but not in the gastrointestinal tract. In summary, ADMET properties suggest that these molecules may be used as a safe treatment against Leishmania.

Assuntos

Antimaláricos , Antiprotozoários , Leishmania , Animais , Antimaláricos/farmacologia , Antimaláricos/química , Simulação de Acoplamento Molecular , Antiprotozoários/farmacologia , Antiprotozoários/química , Relação Estrutura-Atividade

RESUMO

In this study, we report a low cost, fast and unexplored electrochemical synthesis strategy of copper oxide nanoneedles films as well as their morphological and chemical characterization. The nanostructured films were prepared using electrochemical anodization in alkaline electrolyte solutions of ethylene glycol, water and fluoride ions. The film morphology shows nanoneedle-shaped structures, with lengths up to 1-2 µm; meanwhile, high-resolution X-ray photoelectron spectroscopy (HRXPS) and spectroscopy Raman analyses indicate that a mixture of Cu(II) and Cu(I) oxides, or only Cu(I) oxide, is obtained as the percentage of water in the electrolyte solution decreases. A preliminary study was also carried out for the photocatalytic degradation of the methylene blue (MB) dye under irradiation with simulated sunlight in the presence of the nanoneedles obtained, presenting a maximum degradation value of 88% of MB and, thus, demonstrating the potential characteristics of the material investigated in the degradation of organic dyes.

RESUMO

Botrytis cinerea is a ubiquitous necrotrophic filamentous fungal phytopathogen that lacks host specificity and can affect more than 1000 different plant species. In this work, we explored L1 [(E)-2-{[(2-aminopyridin-2-yl)imino]-methyl}-4,6-di-tert-butylphenol], a pyridine Schiff base harboring an intramolecular bond (IHB), regarding their antifungal activity against Botrytis cinerea. Moreover, we present a full characterization of the L1 by NMR and powder diffraction, as well as UV-vis, in the presence of previously untested different organic solvents. Complementary time-dependent density functional theory (TD-DFT) calculations were performed, and the noncovalent interaction (NCI) index was determined. Moreover, we obtained a scan-rate study on cyclic voltammetry of L1. Finally, we tested the antifungal activity of L1 against two strains of Botrytis cinerea (B05.10, a standard laboratory strain; and A1, a wild type strains isolated from Chilean blueberries). We found that L1 acts as an efficient antifungal agent against Botrytis cinerea at 26 °C, even better than the commercial antifungal agent fenhexamid. Although the antifungal activity was also observed at 4 °C, the effect was less pronounced. These results show the high versatility of this kind of pyridine Schiff bases in biological applications.

Assuntos

Antifúngicos , Botrytis/crescimento & desenvolvimento , Piridinas , Antifúngicos/síntese química , Antifúngicos/química , Antifúngicos/farmacologia , Piridinas/síntese química , Piridinas/química , Piridinas/farmacologia

RESUMO

In the search for new quinoid compounds endowed with potential anticancer activity, the synthesis of novel heterodimers containing the cytotoxic 7-phenylaminoisoquinolinequinone and 2-phenylaminonaphthoquinone pharmacophores, connected through methylene and ethylene spacers, is reported. The heterodimers were prepared from their respective isoquinoline and naphthoquinones and 4,4'-diaminodiphenyl alkenes. The access to the target heterodimers and their corresponding monomers was performed both through oxidative amination reactions assisted by ultrasound and CeCl3·7H2O catalysis "in water". This eco-friendly procedure was successfully extended to the one-pot synthesis of homodimers derived from the 7-phenylaminoisoquinolinequinone pharmacophore. The electrochemical properties of the monomers and dimers were determined by cyclic and square wave voltammetry. The number of electrons transferred during the oxidation process, associated to the redox potential EI1/2, was determined by controlled potential coulometry.

Assuntos

Compostos de Anilina/química , Fenômenos Químicos , Técnicas de Química Sintética , Química Verde , Isoquinolinas/química , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Eletroquímica/métodos , Humanos , Isoquinolinas/síntese química , Estrutura Molecular , Polímeros

RESUMO

ß-Cyclodextrin (ßCD), the less water soluble of the cyclodextrins, has been used as a capping agent in the preparation of semiconductor nanocrystals or quantum dots (QDs). Nevertheless, no reports have been found in the use of the highly water-soluble polymer of this, prepared by the crosslinking of the ßCD units with epichlorohydrin in basic medium (ßCDP). This polymer, besides to overcome the low solubility of the ßCD, increases the inclusion constant of the guest; two parameters that deserve its use as capping agent, instead of the native cyclodextrin. In the present manuscript, we afforded the in-situ aqueous preparation of cadmium telluride (CdTe) QDs capped with ßCDP. The polymer influence on the photoluminescent properties of the nanocrystals was analyzed. The ßCDP controls the nanocrystals growth during the Oswald ripening stage. Consequently, the CdTe capped ßCDP QDs showed lower Stokes-shift values, higher photoluminescent efficiency, and narrower size distribution than for nanocrystals obtained in the absence of polymer. Transmission electron microscopy (TEM) micrographs and energy dispersive X-ray spectroscopy (EDS) analysis revealed the composition and crystallinity of the CdTe QDs. This ßCDP capped CdTe QDs is a potential scaffold for the supramolecular modification of QDs surface.

RESUMO

In this study, we explored new properties of the bioinspired pyridine benzimidazole compound B2 (2,4-di-tert-butyl-6-(3H-imidazo[4,5-c]pyridine-2-yl)phenol) regarding its potential use as a differential biomarker. For that, we performed 1D 1HNMR (TOCSY), UV-Vis absorption spectra in different organic solvents, voltammetry profile (including a scan-rate study), and TD-DFT calculations that including NBO analyses, to provide valuable information about B2 structure and luminescence. In our study, we found that the B2 structure is highly stable, where the presence of an intramolecular hydrogen bond (IHB) seems to have a crucial role in the stability of luminescence, and its emission can be assigned as fluorescence. In fact, we found that the relatively large Stokes Shift observed for B2 (around 175 nm) may be attributed to the stability of the B2 geometry and the strength of its IHB. On the other hand, we determined that B2 is biocompatible by cytotoxicity experiments in HeLa cells, an epithelial cell line. Furthermore, in cellular assays we found that B2 could be internalized by passive diffusion in absence of artificial permeabilization at short incubation times (15 min to 30 min). Fluorescence microscopy studies confirmed that B2 accumulates in the endoplasmic reticulum (ER) and Golgi apparatus, two organelles involved in the secretory pathway. Finally, we determined that B2 exhibited no noticeable blinking or bleaching after 1 h of continuous exposure. Thus, B2 provides a biocompatible, rapid, simple, and efficient way to fluorescently label particular organelles, producing similar results to that obtained with other well-established but more complex methods.

RESUMO

It has been reported that the structure of the Schiff bases is fundamental for their function in biomedical applications. Pyridine Schiff bases are characterized by the presence of a pyridine and a phenolic ring, connected by an azomethine group. In this case, the nitrogen present in the pyridine is responsible for antifungal effects, where the phenolic ring may be also participating in this bioactivity. In this study, we synthesized two new pyridine Schiff Bases: (E)-2-[(3-Amino-pyridin-4-ylimino)-methyl]-4,6-difluoro-phenol (F1) and (E)- 2-[(3-Amino-pyridin-4-ylimino)-methyl]-6-fluoro-phenol (F2), which only differ in the fluorine substitutions in the phenolic ring. We fully characterized both F1 and F2 by FTIR, UV-vis, 1H; 13C; 19F-NMR, DEPT, HHCOSY, TOCSY, and cyclic voltammetry, as well as by computational studies (DFT), and NBO analysis. In addition, we assessed the antifungal activity of both F1 (two fluorine substitution at positions 4 and 6 in the phenolic ring) and F2 (one fluorine substitution at position 6 in the phenolic ring) against yeasts. We found that only F1 exerted a clear antifungal activity, showing that, for these kind of Schiff bases, the phenolic ring substitutions can modulate biological properties. In addition, we included F1 and F2 into in epichlorohydrin-ß-cyclodextrin polymer (ßCD), where the Schiff bases remained inside the ßCD as determined by the ki , TGA, DSC, and SBET. We found that the inclusion in ßCD improved the solubility in aqueous media and the antifungal activity of both F1 and F2, revealing antimicrobial effects normally hidden by the presence of common solvents (e.g., DMSO) with some cellular inhibitory activity. The study of structural prerequisites for antimicrobial activity, and the inclusion in polymers to improve solubility, is important for the design of new drugs.

RESUMO

OBJECTIVES: To determine whether the CD4+CD28null T-cells subpopulation predicts the occurrence of damage in SLE. METHODS: This longitudinal study was conducted in consecutive SLE patients seen every six months in our Rheumatology Department since 2012. Patients in whom CD4+CD28null T-cells had been measured and who had at least one subsequent visit were included in the study. Survival analyses (univariable and multivariable Cox-regression models) were performed to determine the risk of overall and domain damage (as per the SLICC Damage Index - SDI) as a function of the frequency of this T-cell subpopulation. The multivariable model was adjusted for pertinent confounders. All analyses were performed using SPSS 21.0. RESULTS: One hundred and nineteen patients were evaluated; their mean (SD) age was 43.5 (11.9) years, 113 (95.0%) were female. Disease duration was 7.8 (7.0) years, the SLEDAI 5.3 (4.1) and the SDI 1.0 (1.4). The percentage of CD4+CD28null T-cells was 17.4 (14.0). The mean follow-up was 2.1 (0.8) years, and the mean number of visits per patient 3.5 (1.1). Forty-six (38.7%) patients increase at least one SDI point. In the univariable and multivariable analyses, the percentage of CD4+CD28null predicted the occurrence of lung damage [HR: 1.042 (CI95%: 1.001-1.085); p=0.047 and HR: 1.099 (CI95%1.020-1.184); p=0.013, respectively] but neither the total SDI score nor all other SDI domain scores were predicted by the percentage of CD4+CD28null cells. CONCLUSIONS: In SLE patients, CD4+CD28null T-cells predict the occurrence of new lung damage, independently of other risk factors but not of overall damage or damage on other domains.

Assuntos

Antígenos CD28/imunologia , Linfócitos T CD4-Positivos/imunologia , Pulmão/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Adulto , Antimaláricos/uso terapêutico , Antígenos CD28/sangue , Antígenos CD28/deficiência , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/metabolismo , Progressão da Doença , Feminino , Humanos , Imunossupressores/uso terapêutico , Estudos Longitudinais , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Peru , Prognóstico , Fatores de Risco , Fatores de Tempo

RESUMO

Introducción:la citología cérvicovaginal es una prueba de tamizaje para detectar las neoplasias intracervicales (NIC), que ha disminuido la incidencia y la mortalidad por cáncer de cuello uterino (CCU). El diagnóstico del NIC es más frecuente entre los 20 y 30 años y el de CCU tiene una mayor frecuencia entre los 30 y 40 años. Desde 1983 a 1991 la tasa de mortalidad por CCU en Colombia fue de 6,5/100.000 habitantes y el 50% de estos casos murieron por diagnóstico tardío. Aunque se divulga que la infección por el papilomavirus es la causa necesaria, no es suficiente para el desarrollo del CCU. Objetivo:determinar una relación entre VPH y el desarrollo de NIC y CCU.Materiales y métodos:se revisaron 11.992 citologías vaginales en el período de un año, y a las VPH positivas por patología se les realizó biopsia de cérvix. Resultados:hay mayor probabilidad de adquirir VPH entre los 30 y 39 años, que se reduce en menores de 19 y mayores de 50 años. Con la sola presencia del virus la probabilidad de desarrollar NIC-I es de 5.8%, la de desarrollar NICII-III es de 0.29% y la de desarrollar CCU es de 0.08%. Conclusiones: se encontraron9 casos de CCU en 735 citologías con VPH diagnosticadas por patología, que corresponde al 1.2%; y una probabilidad del 0.08% para el desarrollo del cáncer, teniendo en cuenta solo la presencia del VPH. Este resultado sugiere que se necesitan otros factores para el desarrollo del cáncer.

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Introduction: cervical Pap smear is a test to detect potentially malignant cervical neoplasia (CIN), which has decreased the incidence and mortality from cervical (cervical cancer) cancer. NIC diagnosis is most common between 20 and 30 years and the cervical cancer has a higher frequency between 30 and 40 years. From 1983 to 1991, the mortality rate for cervical cancer in Colombia was 6.5 / 100,000 and 50% of these cases died late diagnosis. Although it is accepted that infection with human papillomavirus (HPV) is the necessary cause, itis not enough for the development of cervical cancer.Objective:to determine a relationship between HPV and cervical cancer development and NIC.Materials and Methods:11,992 Pap smears were reviewed in the period of one year and a positive HPV pathologyunderwent cervical biopsy.Results:no more likely to get HPV between 30 and 39, which is reduced by less than 19 and older than 50 years. The mere presence of the virus the probability of developing CIN-I is 5.8%, to develop NICII-III is 0.29% and that of developing cervical cancer is 0.08%.Conclusions:9 cases of cervical cancer were found in 735 HPV diagnosed by cytological pathology, corresponding to 1.2%; and a probability of 0.08% to cancer development, taking into account only the presence of HPV. This result suggests that other factors for cancer development are needed.

Assuntos

Humanos , Vírus , Papillomaviridae , Doença

RESUMO

A theoretical protocol to study the sensitization and emission mechanism in lanthanide compounds on the basis of multireference CASSCF/PT2 calculations is proposed and applied to [Eu(NO3)3(dppz-CN)] and [Eu(NO3)3(dppz-NO2)] compounds synthesized and characterized herein. The method consists of a fragmentation scheme where both the ligand and the lanthanide fragments were calculated separately but at the same level of theory, using ab initio wave-function-based methods which are adequate for the treatment of quasi-degenerate states. This is based on the fact that the absorption is ligand-localized and the emission is europium-centered. This characteristic allowed us to describe the most probable energy transfer pathways that take place in the complexes, which involved an ISC between the S1 to T1 ligand states, energy transfer to 5D2 in the lanthanide fragment, and further 5D0 → 7FJ emission. For both compounds, the triplet and 5D2 states were determined at the CASPT2 level to be around ∼26000 and ∼22400 cm-1, respectively. This difference is in the optimal range for the energy transfer process. Finally, the emissive state 5D0 was found at ∼18000 cm-1 and the emission bands in the range 550-700 nm, in quite good agreement with the experimental results.