Synthesis and biological evaluation of novel imidazolidine derivatives as candidates to schistosomicidal agents

ABSTRACT Introduction: Schistosomiasis is an infectious parasitic disease caused by trematodes of the genus Schistosoma, which threatens at least 258 million people worldwide and its control is dependent on a single drug, praziquantel. The aim of this study was to evaluate the anti-Schistosoma mansoni activity in vitro of novel imidazolidine derivatives. Material and methods: We synthesized two novel imidazolidine derivatives: (LPSF/PTS10) (Z)-1-(2-chloro-6-fluorobenzyl)-4-(4-dimethylaminobenzylidene)-5-thioxoimidazolidin-2-one and (LPSF/PTS23) (Z)-1-(2-chloro-6-fluoro-benzyl)-5-thioxo-4-(2,4,6-trimethoxy-benzylidene)-imidazolidin-2-one. The structures of two compounds were determined by spectroscopic methods. During the biological assays, parameters such as motility, oviposition, mortality and analysis by Scanning Electron Microscopy were performed. Results: LPSF/PTS10 and LPSF/PTS23 were considered to be active in the separation of coupled pairs, mortality and to decrease the motor activity. In addition, LPSF/PTS23 induced ultrastructural alterations in worms, after 24 h of contact, causing extensive erosion over the entire body of the worms. Conclusion: The imidazolidine derivatives containing the trimetoxy and benzylidene halogens showed promising in vitro schistosomicidal activity.

Compostos coordenados híbridos de platina no tratamento do câncer / Platinum hybrid coordinated compounds in cancertreatment

O câncer, ou neoplasia, é uma doença caracterizada pela propagação descontrolada de formas anormais das próprias células corporais e corresponde à segunda doença que mais causa mortes no mundo. A história da platina no tratamento do câncer teve início com a descoberta da sua atividade, em 1965, com a aprovação para uso clínico acontecendo apenas após 10 anos. Atualmente, os fármacos com platina estão entre os mais bem sucedidos agentes anticancerígenos, onde se destacam cisplatina (1), carboplatina (2) e oxaliplatina (3). Seus mecanismos de ação são similares: estes fármacos formam adutos com o DNA, impedindo a sua síntese e reparo, levando à morte celular. Contudo, os efeitos adversos desencadeados pelo tratamento e o desenvolvimento de resistência ao medicamento têm limitado suas aplicações. Uma das principais estratégias para a diminuição de tais efeitos consiste em alterar a estrutura destas moléculas, levando à formação de compostos híbridos, que se caracterizam pela presença de pelo menos dois fragmentos funcionais distintos em uma mesma molécula e podem apresentar maior espectro de atividade antitumoral. Dentre as alterações mais comuns encontram-se a modificação da solubilidade, através da inserção de grupos abandonadores mais ou menos hidrofóbicos e a introdução de ligantes com atividade biológica própria. Dessa forma, esta revisão visa verificar os avanços mais recentes na síntese de compostos híbridos de platina, bem como as melhorias na atividade anticâncer dos novos compostos platinados...

Cancer, or neoplasm, is a disease characterized by the uncontrolled propagation of abnormal cells of the body and is the second leading death-causing disease. The history of platinum in cancer treatment goes back to the discovery of its activity in 1965 and its approval for clinical use just 10 years later. Some of the most successful anticancer agents are Pt-based chemotherapeutics, among which cisplatin (1), carboplatin (2), and oxaliplatin (3) stand out. They have similar mechanisms of action: they form adducts with DNA, preventing its synthesis and repair and leading to cell death. However, adverse effects triggered by treatment and the development of resistance to these drugs have limited their application. One of the most important strategies to reduce such effects is to carry out structural modifications of these molecules, leading to hybrid compounds that are characterized by the presence of at least two distinct functional fragments on the same molecule and can exhibit a broader antitumor activity spectrum. Among the most typical modifications are changes to the solubility pattern, created by the insertion of leaving groups with high or low hydrophobicity, and the introduction of biologically active ligands as non-leaving groups. The purpose of these strategies is to obtain compounds capable of reducing systemic toxicity and/or overcoming acquired resistance factors to cisplatin. Therefore, the aim of this review is to discuss the most recent advances in the synthesis of hybrid platinum compounds, as well as improvements in the anticancer activity of Pt-compounds...

Immunological studies and in vitro schistosomicide action of new imidazolidine derivatives

Schistosomiasis is a major public health problem with 207 million people infected and more than 779 million at risk. The drug of choice for treating schistosomiasis is praziquantel (PZQ); however, it is inefficient against immature forms of schistosomes. The aim of this study was to test new imidazolidine derivatives LPSF/PT09 and LPSF/PT10 against adult Schistosoma mansoni worms. IC50, cytotoxicity, immune response and cell viability assays were also available for these imidazolidines. Different concentrations of imidazolidine, from 32 to 320 »M, promoted motor abnormalities in breeding and unpaired worms, and death in 24 hours at higher concentrations. Although LPSF/PT09 and LPSF/PT10 did not affect IFN-³ and IL-10 production, they induced nitric oxide production and showed a similar behavior to praziquantel on cell death test. Thus, these new imidazolidine derivatives should undergo further study to develop schistosomiasis drugs.

New imidazolidinic bioisosters: potential candidates for antischistosomal drugs

The emergence of strains of Schistosoma resistant to praziquantel has drawn attention to the search for new schistosomacide drugs. Imidazolidinic derivatives have performed outstandingly against adult S. mansoni worms when evaluated in vitro. The molecular modification of imidazolidine by way of bioisosteric replacement gives rise to variations in its biological response. This study verifies the potential of substituent groups in the derivatives (Z)3-benzyl-5-(2-fluoro-benzylidene)-imidazolidine-2,4-dione NE4, 3-benzyl-5-(4-chloro-arylazo)-4-thioxo-imidazolidin -2-ona PT5, 3-benzyl-5-(3-fluoro-benzylidene)-1-methyl-2-thioxo-imidazolidin-4-one JT53; 3-benzyl-1-methyl-5-(4-methyl-benzylidene)-2-thioxo-imidazolidin-4-one JT63; 3-benzyl-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo -imidazolidin-4-one JT68; 3-(4-chloro-benzyl)-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo-imidazolidin-4-one JT69; 3-(4-phenyl-benzyl)-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo-imidazolidin-4-one JT72 by determining the viability in vitro of adult S. mansoni worms in the presence of these derivatives. The susceptibility of the worms obtained from mice and kept in culture in the presence of different concentrations was determined by way of schistosomacide kinetic, observed every 24 h over a period of eight days. The results show that the worms were more sensitive to the PT5 derivative at a concentration of 58 æM which killed 100 percent of the worms after 24 h of contact, also giving rise to alterations in the tegument surface of the worms with the formation of bubbles and peeling. These observations suggest a strong electronic contribution of the arylazo grouping in the biological response.