Organocatalytic Synthesis and Antitumor Activity of Novel 1,2,3-triazoles Derived from Fatty ß-ketoesters.

BACKGROUND: Developing methods to synthesize highly functionalized and complex 1,2,3- triazoles from various combinations of substrates remains a significant challenge in organic synthesis. Thus, to the best of our knowledge, an organocatalytic approach to synthesize 1,2,3-triazoles derived from fatty acids has not been explored. OBJECTIVE: In this sense, we describe here the organocatalyzed synthesis and preliminary results of antitumor and cytotoxic activity of a range of 1,2,3-triazoles derived from fatty esters. METHODS: To synthesize 1,2,3-triazoles 3 derived from fatty ß-ketoesters, we performed the reaction of appropriate aryl azides 2a-j with ß -ketoesters 1a-c in the presence of 5 mol% of DBU using DMSO as a solvent at 70 °C for 24 h. The viability of 5637 cells was determined by measuring the reduction of soluble MTT to water-insoluble formazan. The IC50 concentration that inhibits 50% of cell growth and the results were obtained by at least three independent experiments in triplicate for each test. RESULTS: Through enolate-mediated organocatalysis, 1,2,3-triazoles 3 derived from fatty ß-ketoesters were synthesized in moderate to excellent yields by reacting fatty esters 1 with aryl azides 2 in the presence of a catalytic amount of 1,8-diazabicyclo[5.4.0]undec-7-ene (5 mol%). All compounds derived from palmitic acetoacetate 1a were evaluated regarding induced cytotoxicity in vitro in a human bladder cancer cell line, and compounds 3a, 3d, 3e, and 3g were shown to be promising alternatives for bladder cancer treatment and presented the lowest inhibitory concentration of IC50. CONCLUSION: We described a synthetic procedure to prepare 1,2,3-triazoles derived from fatty ß - ketoesters by DBU-catalyzed 1,3-dipolar cycloaddition reactions of fatty esters with different aryl azides. Compounds derived from palmitic acetoacetate were screened for antitumor and cytotoxic activity in vitro in human bladder cancer cell lines, and compounds 3a, 3d, 3e, and 3g showed potential to treat bladder cancer.

Amnesia-ameliorative effect of a quinoline derivative through regulation of oxidative/cholinergic systems and Na+/K+-ATPase activity in mice.

The present study evaluated the anti-amnesic activity of 1-(7-chloroquinolin-4-yl)-5-methyl-N-phenyl-1H-1,2,3-triazole-4-carboxamide (QTCA-1) against scopolamine (SCO)-induced amnesia in mice. It was evaluated cholinergic dysfunction, oxidative stress and Na+/K+-ATPase activity in cerebral cortex and hippocampus of mice. Male Swiss mice were treated with QTCA-1 (10 mg/kg, intragastrically (i.g.), daily) for nine days. Thirty minutes after the treatment with compound, the animals received a injection of SCO (0.4 mg/kg, intraperitoneally (i.p.)). Mice were submitted to the behavioral tasks 30 min after injection of SCO (Barnes maze, open-field, object recognition and location, and step-down inhibitory avoidance tasks) during nine days. In day 9, cerebral cortex and hippocampus of mice were removed to determine the thiobarbituric acid reactive species (TBARS) levels, and catalase (CAT), Na+/K+-ATPase and acetylcholinesterase (AChE) activities. SCO caused amnesia in mice for changing in step-down inhibitory avoidance, Barnes maze, and object recognition and object location tasks. QTCA-1 treatment attenuated the behavioral changes caused by SCO. Moreover, SCO increased AChE and CAT activities, decreased Na+/K+-ATPase activity and increased TBARS levels in the cerebral structures of mice. QTCA-1 protected against these brain changes. In conclusion, QTCA-1 had anti-amnesic action in the experimental model used in the present study, through the anticholinesterase effect, modulation of Na+/K+-ATPase activity and antioxidant action.

7-Chloroquinoline-1,2,3-triazoyl carboxamides induce cell cycle arrest and apoptosis in human bladder carcinoma cells.

In the present study, the antitumoral properties of a series of 7-chloroquinoline-1,2,3-triazoyl-carboxamides (QTCA) were investigated by analyzing their cytotoxic activities against human bladder cells (5637; grade II carcinoma). In addition, their effects on cell viability, cell cycle arrest mechanisms, apoptosis induction, in silico molecular docking, and detection of pro-apoptotic and anti-apoptotic proteins were evaluated. The cytotoxicity assay identified major dose- and time-dependent cytotoxic effects in 5637 cells after they were exposed to treatment with QTCA, only minimal effects were observed on normal cells. A live/dead assay confirmed that significant cell death, arrest in the G0/G1 phase and apoptosis were associated with treatment by 1-(7-Chloroquinolin-4-yl)-5-methyl-N-phenyl-1H-1,2,3-triazole-4-carboxamide (QTCA-1) and 1-(7-Chloroquinolin-4-yl)-N-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazole-4-carboxamide (QTCA-4). The in silico results indicated that these compounds acted through different mechanisms for the induction of cell cycle arrest and apoptosis. Western blotting confirmed the binding of the QTCAs to pro- and anti-apoptotic proteins. In conclusion, QTCA-1 and QTCA-4 are promising candidates for inducing cytotoxicity, cell cycle arrest, and apoptosis in human bladder cancer cells.

O novo Regulamento Sanitário Internacional / The new International Health Regulations

A mais recente revisão do Regulamento Sanitário Internacional (RSI), publicada em 2005, trouxe inovações com o intuito de transpor as limitações enfrentadas pelo regulamento de 1969, que se tornaram cada vez mais aparentes com o ressurgimento de antigas doenças e o aparecimento de novas, nas décadas de 1970 e 1980. Por meio de revisão da literatura, dos regulamentos sanitários internacionais (1951, 1969, 2005) e de sítios eletrônicos de entidades de saúde, foi feito um estudo essencialmente bibliográfico e documental, com o objetivo de identificar e apresentar as ferramentas trazidas pelo novo RSI. Apesar de esse instrumento se mostrar promissor para auxiliar na resposta mundial a um surto, há outros fatores envolvidos, como as diferenças econômicas, políticas, culturais e religiosas entre Estados-Membros da OMS; é preciso considerar que alguns países nãocontam com o mínimo de infraestrutura básica para atender satisfatoriamente situações menos complexas que a transnacionalização dos riscos, e possivelmente jamais conseguirão atender às capacidades nacionais básicas para detectar, avaliar, notificar e informar uma Emergência de Saúde Pública de Importância Internacional (ESPII) sem ajuda técnica e financeira, não prevista expressamente pelo novo instrumento regulatório. Além disso, a visão de que se podem controlar totalmente a ocorrência e o alastramento de eventos em saúde é demasiadamente otimista. Sempre que possível, o intuito do regulamento é evitar a ocorrência de eventos em saúde; porém, quando isso não acontece, o objetivo torna-se minimizar o alastramento e diminuir a gravidade das consequências.