1269703-41-4Relevant articles and documents
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 of 1,4-disubstituted pyrazolo[3,4-d]pyrimidines from 4,6-dichloropyrimidine-5-carboxaldehyde: Insights into selectivity and reactivity
Morrill, Christie,Babu, Suresh,Almstead, Neilg.,Moon, Young-Choon
, p. 1791 - 1806 (2013/07/26)
Strategies for carrying out the reaction of 4,6-dichloropyrimidine-5- carboxaldehyde with both aromatic and aliphatic hydrazines to generate 1-substituted 4-chloropyrazolo[3,4-d]pyrimidines in a selective, high-yielding, and operationally simple manner are presented. For aromatic hydrazines, the reaction is performed at a high temperature in the absence of an external base. For aliphatic hydrazines, the reaction proceeds at room temperature in the presence of an external base. The observed selectivity and reactivity trends are rationalized through consideration of the proposed reaction mechanism. The 1-substituted 4-chloropyrazolo[3,4-d]pyrimidine products serve as versatile synthetic intermediates, through further functionalization of the 4-chloride moiety, enabling the rapid generation of a structurally diverse array of 1,4-disubstituted pyrazolo[3,4-d]pyrimidines. Georg Thieme Verlag Stuttgart. New York.
