51516-67-7Relevant articles and documents
Synthesis of pyrazole-carboxamides and pyrazole-carboxylic acids derivatives: Simple methods to access powerful building blocks
Dos Santos, Maurício Silva,Ferreira, Byanca Silva,Silva, Rafaela Corrêa,Souto, Bernardo Araújo
, p. 335 - 343 (2021/09/07)
Hybrid systems containing pyrazole moiety show a wide spectrum of biological activities. To access novel hybrids with pyrazole ring, in this work we synthesized twenty pyrazole-carboxylic acids and twenty pyrazole-carboxamides, using simple synthetic methods, to be used as building blocks in the development of new structures.
New pyrazolopyrimidine derivatives as Leishmania amazonensis arginase inhibitors
Feitosa, Livia M.,da Silva, Edson R.,Hoelz, Lucas V.B.,Souza, Danielle L.,Come, Julio A.A.S.S.,Cardoso-Santos, Camila,Batista, Marcos M.,Soeiro, Maria de Nazare C.,Boechat,Pinheiro, Luiz C.S.
, p. 3061 - 3069 (2019/06/08)
Arginase performs the first enzymatic step in polyamine biosynthesis in Leishmania and represents a promising target for drug development. Polyamines in Leishmania are involved in trypanothione synthesis, which neutralize the oxidative burst of reactive oxygen species (ROS) and nitric oxide (NO) that are produced by host macrophages to kill the parasite. In an attempt to synthesize arginase inhibitors, six 1-phenyl-1H-pyrazolo[3,4-d]pyrimidine derivatives with different substituents at the 4-position of the phenyl group were synthesized. All compounds were initially tested at 100 μM concentration against Leishmania amazonensis ARG (LaARG), showing inhibitory activity ranging from 36 to 74%. Two compounds, 1 (R=H) and 6 (R=CF3), showed arginase inhibition >70% and IC50 values of 12 μM and 47 μM, respectively. Thus, the kinetics of LaARG inhibition were analyzed for compounds 1 and 6 and revealed that these compounds inhibit the enzyme by an uncompetitive mechanism, showing Kis values, and dissociation constants for ternary complex enzyme-substrate-inhibitor, of 8.5 ± 0.9 μM and 29 ± 5 μM, respectively. Additionally, the molecular docking studies proposed that these two uncompetitive inhibitors interact with different LaARG binding sites, where compound 1 forms more H-bond interactions with the enzyme than compound 6. These compounds showed low activity against L. amazonensis free amastigotes obtained from mice lesions when assayed with as much as 30 μM. The maximum growth inhibition reached was between 20 and 30% after 48 h of incubation. These results suggest that this system can be promising for the design of potential antileishmanial compounds.
Synthesis, structure-activity relationship and trypanocidal activity of pyrazole-imidazoline and new pyrazole-tetrahydropyrimidine hybrids as promising chemotherapeutic agents for Chagas disease
Monteiro,Lechuga,Lara,Souto,Viganó,Bourguignon,Calvet,Oliveira,Alves,Souza-Silva,Santos,Pereira
, (2019/08/20)
Drug therapy for Chagas disease remains a major challenge as potential candidate drugs have failed clinical trials. Currently available drugs have limited efficacy and induce serious side effects. Thus, the discovery of new drugs is urgently needed in the fight against Chagas' disease. Here, we synthesized and evaluated the biological effect of pyrazole-imidazoline (1a-i) and pyrazole-tetrahydropyrimidine (2a-i) derivatives against relevant clinical forms of Trypanosoma cruzi. The structure-activity relationship (SAR), drug-target search, physicochemical and ADMET properties of the major active compounds in vitro were also assessed in silico. Pyrazole derivatives showed no toxicity in Vero cells and also no cardiotoxicity. Phenotypic screening revealed two dichlorinated pyrazole-imidazoline derivatives (1c and 1d) with trypanocidal activity higher than that of benznidazole (Bz) against trypomastigotes; these were also the most potent compounds against intracellular amastigotes. Replacement of imidazoline with tetrahydropyrimidine in the pyrazole compounds completely abolished the trypanocidal activity of series 2(a-i) derivatives. The physicochemical and ADMET properties of the compounds predicted good permeability, good oral bioavailability, no toxicity and mutagenicity of 1c and 1d. Pyrazole nucleus had high frequency hits for cruzipain in drug-target search and structure activity relationship (SAR) analysis of pyrazole-imidazoline derivatives revealed enhanced activity when chlorine atom was inserted in meta-positions of the benzene ring. Additionally, we found evidence that both compounds (1c and 1d) have the potential to interact non-covalently with the active site of cruzipain and also inhibit the cysteine proteinase activity of T. cruzi. Collectively, the data presented here reveal pyrazole derivatives with promise for further optimization in the therapy of Chagas disease.
