RESUMO
A series of non-hydrolysable 5'-aryl substituted GDP analogs has been synthesized by reacting 5'-azido-5'-deoxyguanosine with different aryl- and benzyloxy-alkynes. Cu(I) nanoparticles in water were found to be the most efficient catalyst, producing the desired 5'-arylguanosines with good yields. The synthesized compounds were screened for in vitro antileishmanial activity against Leishmania donovani axenic amastigotes and intramacrophage amastigotes stages. The 4-(3-nitrobenzyl)-1,2,3-triazole 5'-substituted guanosine analog was found to be the most active in the series with an IC50 of 8.6 µM on axenic amastigotes. Despite a rather low in vitro antileishmanial activity on the intramacrophage amastigotes, the absence of cytotoxicity on RAW 264.7 macrophages justifies further pharmacomodulations making this antileishmanial series promising.
Assuntos
Alcinos/química , Antiprotozoários/síntese química , Antiprotozoários/farmacologia , Azidas/química , Desoxiguanosina/análogos & derivados , Leishmania donovani/efeitos dos fármacos , Animais , Antiprotozoários/química , Antiprotozoários/metabolismo , Química Click , Desoxiguanosina/síntese química , Desoxiguanosina/química , Desoxiguanosina/metabolismo , Desoxiguanosina/farmacologia , Leishmania donovani/enzimologia , Manose-6-Fosfato Isomerase/química , Manose-6-Fosfato Isomerase/metabolismo , Camundongos , Simulação de Acoplamento Molecular , Conformação ProteicaRESUMO
Leishmaniases are an ensemble of diseases caused by the protozoan parasite of the genus Leishmania. Current antileishmanial treatments are limited and present main issues of toxicity and drug resistance emergence. Therefore, the generation of new inhibitors specifically directed against a leishmanial target is an attractive strategy to expand the chemotherapeutic arsenal. GDP-Mannose Pyrophosphorylase (GDP-MP) is a prominent therapeutic target involved in host-parasite recognition which has been described to be essential for parasite survival. In this work, we produced and purified GDP-MPs from L. mexicana (LmGDP-MP), L. donovani (LdGDP-MP), and human (hGDP-MP), and compared their enzymatic properties. From a rationale design of 100 potential inhibitors, four compounds were identified having a promising and specific inhibitory effect on parasite GDP-MP and antileishmanial activities, one of them exhibits a competitive inhibition on LdGDP-MP and belongs to the 2-substituted quinoline series.
Assuntos
Antiprotozoários/farmacologia , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Leishmania/efeitos dos fármacos , Leishmania/metabolismo , Nucleotidiltransferases/antagonistas & inibidores , Animais , Antiprotozoários/química , Domínio Catalítico , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/química , Humanos , Camundongos , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Nucleotidiltransferases/química , Nucleotidiltransferases/isolamento & purificação , Nucleotidiltransferases/metabolismo , Ligação Proteica , Células RAW 264.7 , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Relação Estrutura-AtividadeRESUMO
Leishmania is the parasite responsible for the neglected disease leishmaniasis. Its virulence and survival require biosynthesis of glycoconjugates, whose guanosine diphospho-d-mannose pyrophosphorylase (GDP-MP) is a key player. However, experimentally resolved structures of this enzyme are still lacking. We herein propose structural models of the GDP-MP from human and Leishmania donovani. Based on a multiple sequences alignment, the models were built with MODELLER and then carefully refined with all atom molecular dynamics simulations in explicit solvent. Their quality was evaluated against several standard criteria, including their ability to bind GDP-mannose assessed by redocking calculations. Special attention was given in this study to interactions of the catalytic site residues with the enzyme substrate and competitive inhibitors, opening the perspective of medicinal chemistry developments.