New salicylamide and sulfonamide derivatives of quinoxaline 1,4-di-N-oxide with antileishmanial and antimalarial activities

Continuing with the efforts to identify new active compounds against malaria and leishmaniasis, fourteen new 3-amino-1,4-di-N-oxide quinoxaline-2-carbonitrile derivatives were synthesized and evaluated for their in vitro antimalarial and antileishmanial activity against Plasmodium falciparum Colombian FCR-3 strain and Leishmania amazonensis strain MHOM/BR/76/LTB-012A. Further computational studies to analyze graphic SAR and ADME properties were undertaken. Results indicate that compounds with one halogenous group substituted in position 6 and 7 provide an efficient approach for further development of antimalarial and antileishmanial agents. In addition, interesting ADME properties were foun

New quinoxaline 1,4-di-N-oxide derivatives: Trypanosomaticidal activities and enzyme docking simulation

Two series of pyrazol and propenone quinoxaline derivatives were tested for parasiticidal activity (against amastigotes of Leishmania peruviana and trypomastigotes of Trypanosoma cruzi) and for toxicity against proliferative and non-proliferative cells. The pyrazol series was almost inactive against T. cruzi but, 2,6-Dimethyl-3-[5-(3,4,5-trimethoxy-phenyl)-4,5-dihydro-1H-pyrazol-3-yl] - quinoxaline 1,4-dioxide inhibited 50% of Leishmania growth at 8.9 µM with no impact against proliferative kidney cells and low toxicity against Thp-1 and murine macrophages. The compounds of the propenone series were moderately active against T. cruzi. Among them, 2 compounds were particularly interesting: (2E)-1-(7-Fluoro-3-methyl-quinoxalin-2-yl)-3-(3,4,5-trimethoxy-phenyl)-propenone, that showed a selective activity against proliferative cells (cancer and parasites), being inactive against normal murine peritoneal macrophages and (2E)-3-(3,4,5-Trimethoxy-phenyl)-1-(3,6,7-trimethyl-quinoxalin-2-yl)-propenone that was only active against Leishmania and inactive against the other tested cells. Furthermore in silico studies were performed for ADME properties and docking studies, both series of compounds respected the Lipinski’s rules and show linear correlation between tripanosomaticidal activities and LogP. Docking studies revealed that compounds of the second series could interact with the poly (ADP-ribose) polymerase protein of Trypanosoma cruzi

Docking and quantitative structure-activity relationship studies for 3-fluoro-4-(pyrrolo[2,1-f][1,2,4]triazin-4-yloxy)aniline, 3-fluoro-4-(1H-pyrrolo[2,3-b]pyridin-4-yloxy)aniline, and 4-(4-amino-2-fluorophenoxy)-2-pyridinylamine derivatives as c-Met kinase inhibitors

We have performed docking of 3-fluoro-4-(pyrrolo[2,1-f][1,2,4]triazin-4-yloxy)aniline (FPTA), 3-fluoro-4-(1H-pyrrolo[2,3-b]pyridin-4-yloxy)aniline (FPPA), and 4-(4-amino-2-fluorophenoxy)-2-pyridinylamine (AFPP) derivatives complexed with c-Met kinase to study the orientations and preferred active conformations of these inhibitors. The study was conducted on a selected set of 103 compounds with variations both in structure and activity. Docking helped to analyze the molecular features which contribute to a high inhibitory activity for the studied compounds. In addition, the predicted biological activities of the c-Met kinase inhibitors, measured as IC50 values were obtained by using quantitative structure-activity relationship (QSAR) methods: Comparative molecular similarity analysis (CoMSIA) and multiple linear regression (MLR) with topological vectors. The best CoMSIA model included steric, electrostatic, hydrophobic, and hydrogen bond-donor fields; furthermore, we found a predictive model containing 2D-autocorrelation descriptors, GETAWAY descriptors (GETAWAY: Geometry, Topology and Atom-Weight AssemblY), fragment-based polar surface area (PSA), and MlogP. The statistical parameters: cross-validate correlation coefficient and the fitted correlation coefficient, validated the quality of the obtained predictive models for 76 compounds. Additionally, these models predicted adequately 25 compounds that were not included in the training set

Primaquine–quinoxaline 1,4‑di‑N‑oxide hybrids with action on the exo‑erythrocytic forms of Plasmodium induce their efect by the production of reactive oxygen species

Background: The challenge in anti-malarial chemotherapy is based on the emergence of resistance to drugs and the search for medicines against all stages of the life cycle of Plasmodium spp. as a therapeutic target. Nowadays, many molecules with anti-malarial activity are reported. However, few studies about the cellular and molecular mechanisms to understand their mode of action have been explored. Recently, new primaquine-based hybrids as new molecules with potential multi-acting anti-malarial activity were reported and two hybrids of primaquine linked to quinoxaline 1,4-di-N-oxide (PQ–QdNO) were identifed as the most active against erythrocytic, exoerythrocytic and sporogonic stages. Methods: To further understand the anti-malarial mode of action (MA) of these hybrids, hepg2-CD81 were infected with Plasmodium yoelii 17XNL and treated with PQ–QdNO hybrids during 48 h. After were evaluated the production of ROS, the mitochondrial depolarization, the total glutathione content, the DNA damage and proteins related to oxidative stress and death cell. Results: In a preliminary analysis as tissue schizonticidals, these hybrids showed a mode of action dependent on peroxides production, but independent of the activation of transcription factor p53, mitochondrial depolarization and arrest cell cycle. Conclusions: Primaquine–quinoxaline 1,4-di-N-oxide hybrids exert their antiplasmodial activity in the exoeryth‑ rocytic phase by generating high levels of oxidative stress which promotes the increase of total glutathione levels, through oxidation stress sensor protein DJ-1. In addition, the role of HIF1a in the mode of action of quinoxaline 1,4-diN-oxide is independent of biological activity

Trypanocidal properties, structure-activity relationship and computational studies of quinoxaline 1,4-di-N-oxide derivatives

Pyrazole and propenone quinoxaline derivatives were tested against intracellular forms of Leishmania peruviana and Trypanosoma cruzi. Both series were tested for toxicity against proliferative and non-proliferative cells. The pyrazole quinoxaline series was quite inactive against T. cruzi; however, the compound 2,6-dimethyl-3-f-quinoxaline 1,4-dioxide was found to inhibit 50% of Leishmania growth at 8.9 mu M, with no impact against proliferative kidney cells and with low toxicity against THP-1 cells and murine macrophages. The compounds belonging to the propenone quinoxaline series were moderately active against T cruzi. Among these compounds, two were particularly interesting, (2E)-1-(7-fluoro-3-methyl-quinoxalin-2-yl)-3-(3,4,5-trimethoxy-phenyl)-p ropenone and (2E)-3-(3,4,5-trimethoxy-phenyl)-1-(3,6,7-trimethyl-quinoxalin-2-yl)-pro penone. The former possessed selective activity against proliferative cells (cancer and parasites) and was inactive against murine peritoneal macrophages: the latter was active against Leishmania and inactive against the other tested cells. Furthermore, in silico studies showed that both series respected Lipinski's rules and that they confirmed a linear correlation between trypanocidal activities and LogP. Docking studies revealed that compounds of the second series could interact with the poly (ADP-ribose) polymerase protein of Trypanosoma cruzi

New quinoxaline 1,4-di-N-oxide derivatives: Trypanosomaticidal activities and enzyme docking simulation

Two series of pyrazol and propenone quinoxaline derivatives were tested for parasiticidal activity (against amastigotes of Leishmania peruviana and trypomastigotes of Trypanosoma cruzi) and for toxicity against proliferative and non-proliferative cells. The pyrazol series was almost inactive against T. cruzi but, 2,6-Dimethyl-3-[5-(3,4,5-trimethoxy-phenyl)-4,5-dihydro-1H-pyrazol-3-yl] - quinoxaline 1,4-dioxide inhibited 50% of Leishmania growth at 8.9 µM with no impact against proliferative kidney cells and low toxicity against Thp-1 and murine macrophages. The compounds of the propenone series were moderately active against T. cruzi. Among them, 2 compounds were particularly interesting: (2E)-1-(7-Fluoro-3-methyl-quinoxalin-2-yl)-3-(3,4,5-trimethoxy-phenyl)-propenone, that showed a selective activity against proliferative cells (cancer and parasites), being inactive against normal murine peritoneal macrophages and (2E)-3-(3,4,5-Trimethoxy-phenyl)-1-(3,6,7-trimethyl-quinoxalin-2-yl)-propenone that was only active against Leishmania and inactive against the other tested cells. Furthermore in silico studies were performed for ADME properties and docking studies, both series of compounds respected the Lipinski’s rules and show linear correlation between tripanosomaticidal activities and LogP. Docking studies revealed that compounds of the second series could interact with the poly (ADP-ribose) polymerase protein of Trypanosoma cruzi

Aryl piperazine and pyrrolidine as antimalarial agents. Synthesis and investigation of structure-activity relationships

Piperazine and pyrrolidine derivatives were synthesized and evaluated for their capacity to inhibit the growth of Plasmodium falciparum chloroquine-resistant (FCR-3) strain in culture. The combined presence of a hydroxyl group, a propane chain and a fluor were shown to be crucial for the antiplasmodial activity. Five compounds of the aryl-alcohol series inhibited 50% of parasite growth at doses ≤ 10 µM. The most active compound 1-(4-fluoronaphthyl)-3-[4-(4-nitro-2-trifluoromethylphenyl)piperazin-1-yl]propan-1-ol was almost 20 to 40 times more active on Plasmodium falciparum (IC50: 0.5 µM) than on tumorogenic and non tumorogenic cells. Calculated physicochemical parameters showed a good potential for intestinal absorption, but due to difficulty in being solubilised prior to oral administration, it was weakly active against Plasmodium berghei infected mice (ED50: 35%). In silico molecular docking study and molecular electrostatic potential calculation revealed that this compound bound to the active site of Plasmodium plasmepsin II enzyme

Trypanoside, anti-tuberculosis, leishmanicidal, and cytotoxic activities of tetrahydrobenzothienopyrimidines

The synthesis of 2-(5,6,7,8-tetrahydro[1]benzothieno[2,3-d]pyrimidin-4-yl) hydrazone-derivatives (BTPs) and their in vitro evaluation against Trypanosoma cruzi trypomastigotes, Mycobacterium tuberculosis, Leishmania amazonensis axenic amastigotes, and six human cancer cell lines is described. The in vivo activity of the most active and least toxic compounds against T. cruzi and L. amazonensis was also studied. BTPs constitute a new family of drug leads with potential activity against infectious diseases. Due to their drug-like properties, this series of compounds can potentially serve as templates for future drug-optimization and drug-development efforts for use as therapeutic agents in developing countries

Exploring the scope of new arylamino alcohol derivatives: Synthesis, antimalarial evaluation, toxicological studies, and target exploration

Synthesis of new 1-aryl-3-substituted propanol derivatives followed by structure-activity relationship, in silico drug-likeness, cytotoxicity, genotoxicity, in silico metabolism, in silico pharmacophore modeling, and in vivo studies led to the identification of compounds 22 and 23 with significant in vitro antiplasmodial activity against drug sensitive (D6 IC50 ≤ 0.19 μM) and multidrug resistant (FCR-3 IC50 ≤ 0.40 μM and C235 IC50 ≤ 0.28 μM) strains of Plasmodium falciparum. Adequate selectivity index and absence of genotoxicity was also observed. Notably, compound 22 displays excellent parasitemia reduction (98 ± 1%), and complete cure with all treated mice surviving through the entire period with no signs of toxicity. One important factor is the agreement between in vitro potency and in vivo studies. Target exploration was performed; this chemotype series exhibits an alternative antimalarial mechanism

Aprender pensando: estrategias de aprendizaje autoregulado

OBJETIVOS: El objetivo de esta comunicación es presentar una herramienta de autoevaluación del aprendizaje del alumno universitario, a la que se ha denominado Aprender Pensando, utilizada en la actualidad por un grupo de profesores de la Universidad de Valladolid con el fin de promover la mejora del proceso de aprendizaje de sus alumnos. Si bien la mejora del aprendizaje es deseable en cualquier contexto, se vuelve especialmente necesaria en el actual momento de reforma de las enseñanzas universitarias, en el cual el aprendizaje autónomo del alumno pasa a ocupar un primer plano. En el desarrollo de la comunicación, se explicarán los orígenes y evolución de este proyecto, así como el proceso de validación al que fue sometida la herramienta. DESARROLLO: El origen de la herramienta de autoevaluación que ahora presentamos se encuentra en una línea de investigación centrada en el aprendizaje de los alumnos universitarios, en la que la profesora Mª Francisca Calleja, del Departamento de Psicología de la Universidad de Valladolid viene trabajando desde hace más de una década (1994-2008). La experiencia parte de la programación de los créditos prácticos de la asignatura de Procesos Psicológicos Básicos, de cuarto curso de Psicopedagogía, donde se plantea a los alumnos un programa sobre entrenamiento en competencia que supone la realización de una práctica en entrenamiento en autocontrol. El objetivo que se persigue es aplicar estrategias de aprendizaje metacognitivas y de apoyo afectivo (Calleja, 1994). A final de cada curso los estudiantes redactan un autoinforme en el que explican su experiencia diaria sobre cómo actúan, cuándo aprenden, experiencia dirigida a mejorar su proceso de aprendizaje personal. Dichos autoinformes nos dan a conocer una serie de esquemas que los estudiante tienen almacenados sobre las acciones tanto propias como de las personas de su entorn