46 research outputs found
Estrategias de programación de la información económica en la radio española
Los contenidos sobre información económica, financiera y empresarial están presentes tanto en la oferta de las cadenas generalistas –SER, COPE, Onda Cero, Punto Radio y Radio Nacional de España-Radio 1–, como en la de Radio Intereconomía –que se distingue en el mercado de la radio española por ofrecer un “producto radiofónico exclusivo” dirigido a una audiencia interesada en esta especialización–. Asimismo, la fórmula de Radio 5 Todo Noticias también considera la actualidad económica en algunas de sus “variantes horarias”. El propósito de este artículo es profundizar en la oferta de productos radiofónicos especializados en economía para evaluar su presencia y tratamiento en las cadenas radiofónicas españolas entre 2004 y 2007, tanto en la estrategia generalista como especializada. El análisis permitirá establecer una tipología de programas y de temáticas más frecuentes, además de evidenciar las principales estrategias en la programación de este tipo de contenidos
Challenges in Chagas Disease Drug Discovery: a review
Chagas disease or American trypanosomiasis is a neglected tropical disease caused by the parasite Trypanosoma cruzi. Although the number of infected individuals has decreased, about 6-7 million people are infected worldwide. The chemotherapy drugs currently used are limited to benznidazole and nifurtimox. They are effective in acute phase, congenital transmission and children with chronic infection; however, recent clinical trials have shown limitations in adults with chronic infection, presenting drawbacks during the treatment. Thus, there is an urgent need for new effective, safe and affordable drugs to fight against this complex disease. There were high expectations for azole derivatives as they appeared to be the most promising drugs for the treatment of Chagas disease during the last decade; however, the disappointing results obtained so far in clinical trials evidenced the lack of correlation between preclinical and clinical development. Therefore, the feedback obtained from these studies should define the starting point for addressing a roadmap for the drug discovery process in the fight against this disease. To tackle this challenge, it is important to keep in mind the drug target profile, already defined by panels of experts, and the coordinated work involving multi-disciplinary networks focusing not only on the discovery of new drugs but also on the standardization of the protocols that would allow acceleration in the Chagas disease drug discovery process
Quinoxaline 1,4-di-N-oxide derivatives: Interest in the treatment of Chagas disease
More than 100 million people are at risk of contracting Chagas disease. It is estimated that in 2008, Chagas disease was responsible for the death of more than 10,000 people. Despite the fact that there are more than 100 years since the disease was discove
red, safe and effective treatments still have to be found. Therefore, new drugs active against Chagas disease are urgently required. Quinoxaline derivatives show very interesting biological properties (anti-
infective, cytotoxic, anticandida, antiprotozoal)and evaluation of their medicinal chemistry is still in progress. In this regard, we have spent more than a decade in the search for anti-Chagasic agents. In this review, we summarize our on-going work to identify new anti-T. cruzi
agents with the quinoxaline-di-N-oxide scaffold. We present the structure-activity relationship observed among the different substitutions in C-2, C-3, C-6 and C-7 position of the quinoxaline ring. Mais de 100 milhões de pessoas estão em risco de contrair a doença de Chagas.
Estima-se que em 2008, mais de 10.000 pessoas morreram devido a esta patologia. Apesar de a doença ter sido descoberta há mais de 100 anos, ainda é preciso encontrar tratamento seguro e eficaz. Portanto, novos fármacos eficazes contra a doença de Chagas necessitam urgentemente serem descobertos. Derivados de quinoxalina apresentam interessantes propriedades biológicas (anti-
infecciosa, citotóxica, anti-candida, anti-
protozoário) e a avaliação de suas propriedades farmacológicas ainda está em andamento. Com respeito a isso, nós estamos há mais de uma década em busca de agentes anti-chagásicos. Nesta revisão mostramos nosso trabalho em andamento para identificação de novos agentes anti-T. cruzi
com o padrão estrutural quinoxalina-di-N-
óxido e apresentamos a relação estrutura-atividade observada entre as diferentes substituições nas posições C-2, C-3, C-6 e C-7 do anel daquinoxalin
Design and synthesis of novel quinoxaline derivatives as potential candidates for treatment of multidrug-resistant and latent tuberculosis
Abstract
Twenty-four quinoxaline derivatives were evaluated for their antimycobacterial
activity using BacTiter-Glo microbial cell viability assay. Five compounds showed
MIC values < 3.1 μM and IC50 values < 1.5 μM in primary screening and therefore,
they were moved on for further evaluation. Compounds 21 and 18 stand out, showing
MIC values of 1.6 μM and IC50 values of 0.5 and 1.0 μM respectively. Both
compounds were the most potent against three evaluated drug-resistant strains.
Moreover, they exhibited intracellular activity in infected macrophages, considering
log-reduction and cellular viability. In addition, compounds 16 and 21 were potent
against non-replicating M. Tb. and compound 21 was bactericidal. Therefore,
quinoxaline derivatives could be considered for making further advances in the future
development of antimycobacterial agents
Quinoxalinas como potenciales agentes Antimycobacterium tuberculosis: una revisión
La tuberculosis requiere nuevos tratamientos frente a su compleja resistencia como MDR-TB
y XDR-TB. Las quinoxalinas presentan una amplia variedad de propiedades biológicas
antichagásica, antimalarial,antileishmanial, antifungal, antimicobacteriana, antiviral,
antitumoral, anticancerosa, analgésica, antiinflamatoria, antioxidante, antihipertensiva y antitrombótica. En esta revisión se muestra las propiedades y nuevas aproximaciones de derivados de 1,4-di-N-óxido de quinoxalina como potenciales agentes con actividad antimicobacterial. Tuberculosis requires of new treatments against their complex resistance as MDR-TB and XDR-TB. Quinoxalines present a wide variety of biological properties as antichagasic, antimalarial, antileishmanial, antifungal, antibacterial, antiviral, antitumor, anticancer, analgesic, antiinflammatory, antioxidant, antithrombotic and antihypertensive. This review shows the properties and new approaches for 1,4-di-N-oxide quinoxaline derivatives as potential antimycobacterial active agents
1,4-Di-N-oxide quinoxaline-2-carboxamide: Cyclic voltammetry and relationship between electrochemical behavior, structure and anti-tuberculosis activity
To gain insight into the mechanism of action, the redox properties of 37 quinoxaline-2-carboxamide 1,4-di-N-oxides with varying degrees of anti-tuberculosis activity were studied in dimethylformamide (DMF) using cyclic voltammetry and first derivative cyclic voltammetry. For all compounds studied, electrochemical reduction in DMF is consistent with the reduction of the N-oxide functionality to form a radical anion. The influence of molecular structure on reduction potential is addressed and it can be said that a general relationship exists between reduction potential and reported antimicrobial activity. For those compounds which have demonstrated promising biological activity, the more active the compound the less negative the reduction potential typically is. The results suggest the possible participation of charge transfer processes in the mechanism of action of quinoxaline di-N-oxides against tuberculosis and offer new insights into the design of future antitubercular drugs
Synthesis and antimycobacterial activity of new quinoxaline-2- carboxamide 1,4-di-N-oxide derivatives.
As a continuation of our research and with the aim of obtaining new anti-tuberculosis agents which can improve the current chemotherapeutic anti-tuberculosis treatments, forty-three new quinoxaline-2-carboxamide 1,4-di-N-oxide derivatives were synthesized and evaluated for in vitro anti-tuberculosis activity against Mycobacterium tuberculosis strain H37Rv. Active compounds were also screened to assess toxicity to a VERO cell line. Results indicate that compounds with a methyl moiety substituted in position 3 and unsubstituted benzyl substituted on the carboxamide group provide an efficient approach for further development of anti-tuberculosis agents
Synthesis and biological evaluation of new quinoxaline derivatives as antioxidant and anti-inflammatory agents
We report the synthesis, anti-inflammatory and antioxidant activities of novel quinoxaline and quinoxaline 1,4-di-N-oxide derivatives. Microwave assisted methods have been used in order to optimize reaction times and to improve the yields. The tested compounds presented important scavenging activities and promising in vitro inhibition of soybean lipoxygenase. Two of the best lipoxygenase inhibitors (compounds 7b and 8f) were evaluated as in vivo anti-inflammatory agents using the carrageenin-induced edema model. One of them (compound 7b) showed important in vivo anti-inflammatory effect (41%) similar to that of indomethacin (47%) used as the reference drug
In vitro antileishmanial activity and iron superoxide dismutase inhibition of arylamine Mannich base derivatives
Leishmaniasis is one of the world’s most neglected diseases, and it has a worldwide prevalence of 12 million. There are no effective human vaccines for its prevention, and treatment is hampered by outdated drugs. Therefore, research aiming at the development of new therapeutic tools to fight Leishmaniasis remains a crucial goal today. With this purpose in mind, we present twenty arylaminoketone derivatives with a very interesting in vitro and in vivo efficacy against Trypanosoma cruzi that have now been studied against promastigote and amastigote forms of L. infantum, L. donovani and L. braziliensis strains. Six out of the twenty Mannich base-type derivatives showed Selectivity Index between 39 and 2337 times higher in the amastigote form than the reference drug glucantime. These six derivatives affected the parasite infectivity rates; the result was lower parasite infectivity rates than glucantime tested at a IC25 dose. In addition, these derivatives were substantially more active against the three Leishmania species tested than glucantime. The mechanism of action of these compounds has been studied, showing a greater alteration in glucose catabolism and leading to greater levels of Fe-SOD (iron superoxide dismutase) inhibition. These molecules could be potential candidates for Leishmaniasis chemotherapy
Development, validation and application of a GC-MS method for the simultaneous detection and quantification of neutral lipid species in Trypanosoma cruzi
The development and validation of an analytical method for the simultaneous
analysis of five neutral lipids in Trypanosoma cruzi epimastigotes by GC-MS is
presented in this study. The validated method meets all validation parameters for all
components and the chromatographic conditions have been optimized during its
development. This analytical method has demonstrated good selectivity, accuracy,
within-day precision, recovery and linearity in each of the established ranges. In
addition, detection and quantification limits for squalene, cholesterol, ergosterol and
lanosterol have been improved and it is worth highlighting the fact that this is the first
time that squalene-2,3-epoxide validation data have been reported. The new validated
method has been applied to epimastigotes treated with compounds with in vitro anti-
T.cruzi activity. This new methodology is straightforward and constitutes a tool for
screening possible sterol biosynthesis pathway inhibitors in Trypanosoma cruzi, one of
the most studied targets in Chagas disease treatment. Therefore, it is an interesting and
useful contribution to medicinal chemistry research