Ortho-nitrobenzyl derivatives as potential anti-schistosomal agents

In the search for new anti-schistosomal agents, a series of fifteen ortho-nitrobenzyl derivatives was assayed in vitro against both the schistosomulum (somule) and adult forms of Schistosoma mansoni. Compounds 8 and 12 showed significant activity against somules at low micromolar concentrations, but none was active against adults. The SAR demonstrated that the compounds most active against the parasite were mutagenic to the human cell line RKO-AS45-1 only at concentrations 10- to 40-fold higher than the worm-killing dose. Given their electrophilicity, compounds were also screened as inhibitors of the S. mansoni cysteine protease (cathepsin B1) in vitro. Amides 5 and 15 exhibited a modest inhibition activity with values of 55.7 and 50.6 % at 100 µM, respectively. The nitrobenzyl compounds evaluated in this work can be regarded as hits in the search for more active and safe anti-schistosomal agents

Atividade antiplasmodial e modelagem molecular de novas chalconas e derivados

Malaria is an infection caused by Plasmodium sp. and It can be serious, if not treated precociously. It affects significant fraction of humanity and has profound health impact worldwide. It is estimated that 3.3 billion people are exposed to the risk of transmission. One of the problems of the infection is the growing emergence of parasite resistance to antimalarial drugs. In this context, studies are needed to develop new alternative chemotherapy. Many substances, such as the chalcones, have had their antiplasmodial activity proven. However, the physicochemical properties of these molecules, which are important for biological actions, are not well established. In this work, molecular modeling was performed and the antiplasmodial activity was evaluated of two chalcones (HBR1, and LH2) and four derivatives of chalcones (GH3, IV4, LCH1, and LCH3). For that, we determined the drug concentration inhibitory of 50% of the growth of P. falciparum in vitro as well as the physicochemical properties of derivatives of chalcones as HOMO, LUMO, electrostatic potential, C log P, hydration energy, polarizability and molecular volume through virtual calculations. The results of the calculated values were correlated with the biological activity in order to identify chemical parameters that can influence the antiplasmodial action. The inhibitory concentrations in 50% of the growth of P. falciparum ranged from 0,2 to 1,7 M, and these values were smaller than described them in the literature. The study of the correlation between the biological activities and the physicochemical properties showed determinating parameters for the biological activity, as LUMO, electrostatic potential, C log P and hydration energy, which may help in the selection of molecules more active against P. falciparum. Thus, these molecular properties can be used in the rational planning of new chalcones and/or derivatives with antiplasmodial activity.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorA malária é uma infecção causada pelo Plasmodium sp. e pode ser grave, se não tratada precocemente. Ela acomete importante fração da humanidade e tem profundo impacto sanitário mundial. Estima-se que 3,3 bilhões de pessoas estejam expostas ao risco de transmissão. Um dos problemas inerentes à infecção é o progressivo aumento da resistência do parasito aos antimaláricos. Nesse contexto, fazem-se necessários estudos para o desenvolvimento de novas alternativas quimioterápicas. Muitas substâncias têm atividade antiplasmodial comprovada, como as chalconas. Entretanto, as propriedades fisico-químicas dessas moléculas, que são importantes para suas ações biológicas, não estão bem estabelecidas. Neste trabalho, foi realizada a modelagem molecular e avaliada a atividade antiplasmodial de duas chalconas (HBR1 e LH2) e quatro derivados de chalconas (GH3, IV4, LCH1 e LCH3). Para isso, foram determinadas: as concentrações inibitórias em 50% do crescimento do P. falciparum in vitro e as propriedades físico-químicas das substâncias, como HOMO, LUMO, potencial eletrostático, C log P, energia de hidratação, polarizabilidade e volume molecular, através de cálculos virtuais. Os resultados dos valores calculados foram correlacionados com a atividade biológica, a fim de se identificar parâmetros químicos que possam influenciar a ação antiplasmodial. As concentrações inibitórias em 50% do crescimento do P. falciparum variaram de 0,2 a 1,7 μM, sendo que estes valores foram menores do que os descritos na literatura. O estudo da correlação entre as atividades biológicas e as propriedades fisico-químicas mostraram parâmetros determinantes de atividade biológica, como LUMO, potencial eletrostático, C log P e energia de hidratação, que podem auxiliar na seleção de moléculas mais ativas contra o P. falciparum. Assim, essas propriedades moleculares podem ser utilizadas no planejamento racional de novas chalconas e/ou derivados com atividade antiplasmodial

Ortho-nitrobenzyl derivatives as potential anti-schistosomal agents

ABSTRACT In the search for new anti-schistosomal agents, a series of fifteen ortho-nitrobenzyl derivatives was assayed in vitro against both the schistosomulum (somule) and adult forms of Schistosoma mansoni. Compounds 8 and 12 showed significant activity against somules at low micromolar concentrations, but none was active against adults. The SAR demonstrated that the compounds most active against the parasite were mutagenic to the human cell line RKO-AS45-1 only at concentrations 10- to 40-fold higher than the worm-killing dose. Given their electrophilicity, compounds were also screened as inhibitors of the S. mansoni cysteine protease (cathepsin B1) in vitro. Amides 5 and 15 exhibited a modest inhibition activity with values of 55.7 and 50.6 % at 100 µM, respectively. The nitrobenzyl compounds evaluated in this work can be regarded as hits in the search for more active and safe anti-schistosomal agents

New 1,3-thiazole derivatives and their biological and ultrastructural effects on Trypanosoma cruzi

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2016-12-13T14:26:25Z No. of bitstreams: 1 Gomes PATM New 1,3-thiazole derivatives....pdf: 2013088 bytes, checksum: 8ca722694d65ed4ac9b209d95a69248c (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2016-12-13T16:21:46Z (GMT) No. of bitstreams: 1 Gomes PATM New 1,3-thiazole derivatives....pdf: 2013088 bytes, checksum: 8ca722694d65ed4ac9b209d95a69248c (MD5)Made available in DSpace on 2016-12-13T16:21:46Z (GMT). No. of bitstreams: 1 Gomes PATM New 1,3-thiazole derivatives....pdf: 2013088 bytes, checksum: 8ca722694d65ed4ac9b209d95a69248c (MD5) Previous issue date: 2016CNPq; CAPES; PRONEX-FAPESB; PRONEM/FACEPE/CNPq.Universidade Federal de Pernambuco. Centro de Ciências da Saúde. Departamento de Ciências Farmacêuticas. Recife, PE, BrasilUniversidade Federal de Pernambuco. Centro de Ciências da Saúde. Departamento de Ciências Farmacêuticas. Recife, PE, BrasilUniversidade Federal de Pernambuco. Centro de Ciências da Saúde. Departamento de Ciências Farmacêuticas. Recife, PE, BrasilUniversidade de Pernambuco. Petrolina, PE, BrasilUniversidade Federal de Pernambuco. Centro de Ciências da Saúde. Departamento de Ciências Farmacêuticas. Recife, PE, BrasilUniversidade Federal de Pernambuco. Centro de Ciências da Saúde. Departamento de Ciências Farmacêuticas. Recife, PE, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Recife, PE, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Recife, PE, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Recife, PE, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Recife, PE, BrasilMinistry of Education of Brazil. CAPES Foundation. Brasília, DF, Brasil / Universidade Federal de Minas Gerais. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, BrasilUniversidade Federal de Minas Gerais. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, BrasilUniversidade Federal de Pernambuco. Centro de Ciências da Saúde. Departamento de Ciências Farmacêuticas. Recife, PE, BrasilIn previous studies, the compound 3-(bromopropiophenone) thiosemicarbazone was described as a potent anti-Trypanosoma cruzi and cruzain inhibitor. In view to optimize this activity, 1,3-thiazole core was used as building-block strategy to access new lead generation of anti T. cruzi agents. In this way a series of thiazole derivatives were synthesized and most of these derivatives exhibited antiparasitic activity similar to benznidazole (Bzd). Among them, compounds (1c) and (1g) presented better selective index (SI) than Bzd. In addition, compounds showed inhibitory activity against the cruzain protease. As observed by electron microscopy, compound (1c) treatment caused irreversible and specific morphological changes on ultrastructure organization of T. cruzi, demonstrating that this class of compounds is killing parasites

Synthesis of a sugar-based thiosemicarbazone series and structure-activity relationship versus the parasite cysteine proteases: rhodesain; cruzain and Schistosoma mansoni cathepsin B1

Submitted by Nuzia Santos ([email protected]) on 2016-01-28T12:27:26Z No. of bitstreams: 1 Synthesis of a Sugar-Based Thiosemicarbazone Series and Structure-Activity.pdf: 4194394 bytes, checksum: eac1a47b149b813e4fa83f370992048c (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2016-01-28T12:38:57Z (GMT) No. of bitstreams: 1 Synthesis of a Sugar-Based Thiosemicarbazone Series and Structure-Activity.pdf: 4194394 bytes, checksum: eac1a47b149b813e4fa83f370992048c (MD5)Made available in DSpace on 2016-01-28T12:38:57Z (GMT). No. of bitstreams: 1 Synthesis of a Sugar-Based Thiosemicarbazone Series and Structure-Activity.pdf: 4194394 bytes, checksum: eac1a47b149b813e4fa83f370992048c (MD5) Previous issue date: 2015Universidade Federal de Minas Gerais. Faculdade de Farmácia. Departamento de Produtos Farmacêuticos. Belo Horizonte, MG, BrasilUniversidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, BrasilUniversidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, BrasilUniversidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, Brasil/Ministerio da Educação. Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. Brasília, DF, BrasilUniversity of California. Skaggs School of Pharmacy and Pharmaceutical Sciences. San Diego, CA, USAUniversity of California. Center for Discovery and Innovation in Parasitic Diseases and Department of Pathology. San Francisco, CA, USAUniversity of California. Center for Discovery and Innovation in Parasitic Diseases and Department of Pathology. San Francisco, CA, USAUniversity of California. Center for Discovery and Innovation in Parasitic Diseases and Department of Pathology. San Francisco, CA, USAUniversidade Federal de Minas Gerais. Faculdade de Farmácia. Departamento de Produtos Farmacêuticos. Belo Horizonte, MG, BrasilUniversidade Federal de Minas Gerais. Faculdade de Farmácia. Departamento de Produtos Farmacêuticos. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, Brasil/Universidade Federal de Santa Catarina. Departamento de Microbiologia, Imunologia e Parasitologia. Florianópolis, SC, BrasilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrasilUniversity of California. Skaggs School of Pharmacy and Pharmaceutical Sciences. San Diego, CA, USAUniversity of California. Center for Discovery and Innovation in Parasitic Diseases and Department of Pathology. San Francisco, CA, USAUniversidade Federal de Minas Gerais. Faculdade de Farmácia. Departamento de Produtos Farmacêuticos. Belo Horizonte, MG, BrasilUniversidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, BrasilThe pressing need for better drugs against Chagas disease, African sleeping sickness, and schistosomiasis motivates the search for inhibitors of cruzain, rhodesain, and Schistosoma mansoni CB1 (SmCB1), the major cysteine proteases from Trypanosoma cruzi, Trypanosoma brucei, and S. mansoni, respectively. Thiosemicarbazones and heterocyclic analogues have been shown to be both antitrypanocidal and inhibitory against parasite cysteine proteases. A series of compounds was synthesized and evaluated against cruzain, rhodesain, and SmCB1 through biochemical assays to determine their potency and structure-activity relationships (SAR). This approach led to the discovery of 6 rhodesain, 4 cruzain, and 5 SmCB1 inhibitors with 50% inhibitory concentrations (IC50s) of ≤ 10 μM. Among the compounds tested, the thiosemicarbazone derivative of peracetylated galactoside (compound 4i) was discovered to be a potent rhodesain inhibitor (IC50 = 1.2 ± 1.0 μM). The impact of a range of modifications was determined; removal of thiosemicarbazone or its replacement by semicarbazone resulted in virtually inactive compounds, and modifications in the sugar also diminished potency. Compounds were also evaluated in vitro against the parasites T. cruzi, T. brucei, and S. mansoni, revealing active compounds among this series